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                                                                     EXHIBIT 9.1

                             ON-SITE SOURCING, INC.
                                VOTING AGREEMENT

         VOTING AGREEMENT, dated this 27th day of September, 2000, by and
between ON-SITE SOURCING, INC., a Delaware corporation ("ONSS"), and C. Gregory
Earls, James V. Warren, Jonathan Ledecky, Northwood Ventures LLC and Northwood
Capital Partners LLC (each, a "Stockholder" and, collectively, the
"Stockholders").

                                    RECITALS:

         WHEREAS, the Stockholders currently beneficially own (as such term is
used under the Securities Exchange Act of 1934, as amended, and the rules and
regulations issued thereunder) the shares of common stock, par value $0.01 per
share ("Shares"), of U.S. Technologies Inc., a Delaware corporation ("USXX"),
shown on Schedule A; and

         WHEREAS, as a condition of entering into the Agreement and Plan of
Merger, made as of the date hereof, by and between USXX and ONSS (the "Merger
Agreement"), ONSS has requested that the Stockholders agree, and the
Stockholders have agreed (i) to enter into a voting agreement and (ii) to give
ONSS an irrevocable proxy, coupled with an interest, to vote the Shares held by
the Stockholders, in each case as more fully set forth herein;

                                   AGREEMENTS:

         NOW, THEREFORE, in consideration of the mutual covenants and agreements
set forth herein, the parties hereby agree as follows:

         1.       Agreement to Vote Shares. Each Stockholder agrees during the
                  term of this Agreement to vote, or cause to be voted, the
                  Shares shown opposite the Stockholder's name on Schedule A
                  hereto and any other Shares acquired after the date hereof, in
                  person or by proxy, in favor of any proposal presented to
                  stockholders that is reasonably necessary to consummate the
                  Merger, including the amendment to USXX' Restated Certificate
                  of Incorporation ("the Charter Amendment"), and, if any
                  separate vote occurs, the Merger (as defined in the Merger
                  Agreement), the adoption and approval of the Merger Agreement
                  (without any material changes thereto) and the approval of the
                  transactions contemplated by the Merger Agreement at every
                  meeting of the stockholders of USXX at which such matters are
                  considered and at every adjournment thereof.

         2.       Grant of Irrevocable Proxy. Each Stockholder hereby grants to
                  ONSS an irrevocable proxy, which proxy is coupled with an
                  interest because of the consideration recited herein, to
                  exercise, at any time and from time to time, all rights and
                  powers of the Stockholder with respect to the Shares shown
                  opposite


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                  the Stockholder's name on Schedule A hereto to vote, give
                  approvals, and receive and waive notices of meetings for
                  purposes of securing the approval and adoption by the
                  stockholders of USXX of the Merger Agreement (without any
                  material changes thereto) and the consummation of the
                  transactions contemplated thereby and to prevent any action
                  that would prevent or hinder in any material respect such
                  approval or consummation. By giving this proxy, each
                  Stockholder hereby revokes any other proxy granted by the
                  Stockholder to vote on any of the Shares in a manner
                  inconsistent with the foregoing grant. The power and authority
                  hereby conferred shall not be terminated by any act of the
                  Stockholder or by operation of law, by the dissolution of, by
                  lack of appropriate power of authority, or by the occurrence
                  of any other event or events and shall be binding upon all of
                  its successors and assigns.

         3.       No Other Grant of Proxy. Except for (i) the Proxy Agreement
                  dated, April 12, 2000, by and among, USV, James V. Warren and
                  C. Gregory Earls and (ii) the Voting Agreement dated, April
                  12, 2000, by and among, E2E, USXX, USV, James V. Warren,
                  Northwood Ventures LLC, Northwood Capital Partners LLC and
                  Jonathan Ledecky, each Stockholder will not, directly or
                  indirectly, grant any proxies or powers of attorney with
                  respect to the Shares shown opposite the Stockholder's name on
                  Schedule A hereto or acquired after the date hereof to any
                  person in connection with its vote, consent or other approval
                  sought, in favor of the Merger (as defined in the Merger
                  Agreement), the adoption and approval of the Merger Agreement
                  and the approval of the transactions contemplated by the
                  Merger Agreement, other than as set forth in Sections 1 and 2
                  hereof.

         4.       Transfers. Each Stockholder will not, nor will such
                  Stockholder permit any entity under such Stockholder's control
                  to, sell, transfer, pledge, assign or otherwise dispose of
                  (including by gift) (collectively, "Transfer"), or consent to
                  any Transfer of, any Shares or any interest therein or enter
                  into any contract, option or other agreement or arrangement
                  (including any profit sharing or other derivative arrangement)
                  with respect to the Transfer of, any Shares or any interest
                  therein to any person, unless prior to any such Transfer the
                  transferee of such Shares agrees to be subject to the
                  provisions of this Agreement.

         5.       Representations and Warranties of the Stockholders. Each
                  Stockholder, as to such Stockholder, hereby represents and
                  warrants to, and covenants with, ONSS as follows:

                  (a)      The Stockholder beneficially owns with power to vote
                           the number of Shares shown opposite the Stockholder's
                           name on Schedule A free and clear of any and all
                           liens, charges, encumbrances, covenants, conditions,
                           restrictions, voting trust arrangements, options and
                           adverse claims or rights whatsoever, except as
                           granted hereby or as would have no adverse effect


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                           on this Agreement and/or the proxy granted hereby.
                           The Stockholder does not own of record or
                           beneficially any shares of capital stock of USXX or
                           other securities representing or convertible into
                           shares of capital stock of USXX except as set forth
                           in the preceding sentence;

                  (b)      The Stockholder has the full right, power and
                           authority to enter into this Agreement and to grant
                           an irrevocable proxy to ONSS with respect to the
                           Shares; there are no options, warrants, calls,
                           commitments or agreements of any nature whatsoever
                           pursuant to which any person will have the right to
                           purchase or otherwise acquire the Shares owned by the
                           Stockholder except as would, if exercised, require
                           such purchaser or acquiror to abide by this Agreement
                           and the proxy granted hereby with respect thereto;
                           except as provided in this Agreement, the Stockholder
                           has not granted or agreed to grant any proxy or
                           entered into any voting trust, vote pooling or other
                           agreement with respect to the right to vote or give
                           consents or approvals of any kind and as to the
                           Shares which proxy, trust, pooling or other agreement
                           remains in effect as of the date hereof and is in
                           conflict with this Agreement or the proxy granted
                           hereby;

                  (c)      The Stockholder is not a party to, subject to or
                           bound by any agreement or judgment, order, writ,
                           prohibition, injunction or decree of any court or
                           other governmental body that would prevent the
                           execution, delivery or performance of this Agreement
                           by the Stockholder or the exercise of proxy rights by
                           ONSS with respect to the Shares;

                  (d)      This Agreement has been duly and validly executed and
                           delivered by the Stockholder and constitutes a legal,
                           valid and binding obligation of the Stockholder,
                           enforceable in accordance with its terms, subject
                           only to (i) the effect of bankruptcy, insolvency,
                           reorganization or moratorium laws or other laws
                           generally affecting the enforceability of creditors'
                           rights and (ii) general equitable principles which
                           may limit the right to obtain specific performance or
                           other equitable remedies; and

                  (e)      The Stockholder will take all commercially reasonable
                           action necessary in order that its representations
                           and warranties set forth in this Agreement shall
                           remain true and correct.

         6.       Stockholders' Covenants. Each Stockholder shall not enter into
                  any voting trust agreement, give any proxy or other right to
                  vote the Shares or take any action that would limit the rights
                  of any holder of the Shares to exercise fully the right to
                  vote such Shares that would be in conflict with this Agreement
                  or the proxy granted hereby.


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         7.       Severability. If any term, provision, covenant or restriction
                  of this Agreement is held by a court of competent jurisdiction
                  to be invalid, void or unenforceable, the remainder of the
                  terms, provisions, covenants and restrictions of this
                  Agreement shall remain in full force and effect and shall in
                  no way be affected, impaired or invalidated.

         8.       Assignment. Except as otherwise provided in Section 4, this
                  Agreement shall not be assigned or delegated by any party
                  hereto, except that any assignment of any of the Shares by any
                  Stockholder shall require that such Shares remain subject to
                  this Agreement and the proxy granted hereby. This Agreement
                  shall be binding upon and inure to the benefit of ONSS and its
                  successors and assigns and shall be binding upon and inure to
                  the benefit of the Stockholders and their permitted successors
                  and any permitted assigns.

         9.       Specific Performance. The parties hereto acknowledge that
                  damages would be an inadequate remedy for a breach of this
                  Agreement and that the obligations of the parties hereto shall
                  be specifically enforceable. In addition to any other legal or
                  equitable remedies to which ONSS would be entitled, in the
                  event of a breach or a threatened breach of this Agreement by
                  any Stockholder, ONSS shall have the right to obtain equitable
                  relief, including (but not limited to) an injunction or order
                  of specific performance of the terms hereof from a court of
                  competent jurisdiction.

         10.      Amendments. This Agreement may not be modified, amended,
                  altered or supplemented except upon the execution and delivery
                  of a written agreement executed by all of the parties hereto.

         11.      Notices. All notices, requests, claims, demands and other
                  communications hereunder shall be in writing and shall be
                  deemed given if delivered personally, by cable, telegram or
                  telex, or mailed by a party hereto by registered or certified
                  mail (return receipt requested) or by a nationally recognized
                  overnight mail delivery service, to other party at the
                  following addresses (or such other address for a party as
                  shall be specified by like notice):

                  If to ONSS:         c/o On-Site Sourcing, Inc.
                                      1111 North 19th Street, Sixth Floor
                                      Arlington, VA 22209
                                      Attn: Christopher J. Weiler
                                      Fax No.: (703)276-8607

                  with a copy to:     King & Spalding
                                      1730 Pennsylvania Avenue, NW
                                      Washington, D.C. 20006-4707
                                      Attn: Glenn C. Campbell, Esq.


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                                          Fax No.: (202) 626-3737

                  if to any Stockholder,
                  to such Stockholder:
                                          U.S. Technologies Inc. 1130
                                          Connecticut Avenue, NW, Suite 700
                                          Washington, D.C.  20036 Attn: C.
                                          Gregory Earls Co-Chairman and Co-Chief
                                          Executive Officer Fax No.: (202)
                                          466-4557

                  with a copy to:         Fleischman and Walsh, L.L.P.
                                          1400 Sixteenth Street, NW, 6th Floor
                                          Washington, D.C. 20036 Attn: Stephen
                                          A. Bouchard, Esq. Fax No.: (202)
                                          265-5706

Any party may change its address for notice by notice so given.

         12.      Governing Law. This Agreement shall be governed by, and
                  construed in accordance with, the laws of the State of
                  Delaware regardless of the laws that might otherwise govern
                  under applicable principles of conflicts of laws.

         13.      Counterparts. This Agreement may be executed in several
                  counterparts, each of which shall be an original, but all of
                  which together shall constitute one and the same agreement.

         14.      Term. This Agreement and the proxy granted herein shall
                  terminate automatically, upon the consummation of the Merger
                  in accordance with and as defined in the Merger Agreement or
                  such other expiration or termination of the Merger Agreement
                  in accordance with its terms (including, without limitation,
                  termination in accordance with Section 8.2(i) of the Merger
                  Agreement on March 31, 2001 if the closing has not occurred
                  prior thereto and on June 30, 2001 if the closing has not
                  occurred by such date because the conditions precedent to the
                  closing set forth in Section 7.2(h) have not been fulfilled),
                  and thereafter this Agreement shall be of no further force or
                  effect and there shall be no liability on the part of any
                  party with respect thereto except nothing herein will relieve
                  any party from liability for any prior breach hereof.

            [THE REMAINDER OF THIS PAGE IS INTENTIONALLY LEFT BLANK]


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IN WITNESS WHEREOF, ONSS has caused this Agreement to be duly executed, and each
Stockholder has duly executed this Agreement, on the day and year first above
written.

                                            ON-SITE SOURCING, INC.,


                                            By: /s/ Christopher J. Weiler
                                               ---------------------------------
                                            Name: Christopher J. Weiler
                                            Title: Chairman and Chief
                                                      Executive Officer


                                            /s/ C. Gregory Earls
                                            ------------------------------------
                                            C. Gregory Earls


                                            /s/ James V. Warren
                                            ------------------------------------
                                            James V. Warren


                                            /s/ Jonathan Ledecky
                                            ------------------------------------
                                            Jonathan Ledecky

                                            NORTHWOOD VENTURES LLC


                                            By: /s/ Henry T. Wilson
                                               ---------------------------------
                                            Name: Henry T. Wilson
                                            Title: Managing Director

                                            NORTHWOOD CAPITAL PARTNERS LLC


                                            By: /s/ Henry T. Wilson
                                               ---------------------------------
                                            Name: Henry T. Wilson
                                            Title: Managing Director


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                                   SCHEDULE A



                  Stockholder                                 Number of Shares
                  -----------                                 ----------------

                                                           
                  C. Gregory Earls(1)                         6,663,660 shares of Common Stock.
                                                              593,500 shares of Series A Stock,
                                                              convertible into 48,647,533 shares of
                                                              Common Stock.
                                                              2,120 share of Series C Stock,
                                                              convertible into 1,462,068 shares of
                                                              Common Stock

                  James V. Warren                             6,357,152 share of Common Stock

                  Jonathan Ledecky                            52,641.81 shares of Series B Stock,
                                                              convertible into 26,320,925 shares of
                                                              Common Stock


                  Northwood Ventures LLC                      49,656.77 shares of Series B Stock,
                                                              convertible into 24,828,385 shares of
                                                              Common Stock

                  Northwood Capital Partners LLC              7,094.17 shares of Series B Stock,
                                                              convertible into 3,547,085 shares of
                                                              common stock


- ---------------

         1 The amount shown includes: 6,266,660 shares of common stock held
directly by USV Partners LLC; and 297,000 shares of common stock owned directly
by Equitable Production Funding, Inc., of which Mr. Earls is the majority owner.
Of the amount shown, 564,340 shares of the Series A Stock and all 2,120 shares
of the Series C Stock are held directly by USV. For purposes of Rule 13d-3 of
the Securities Exchange Act of 1934, Mr. Earls is deemed to be the beneficial
owner of all the shares owned by USV and Equitable Production Funding, Inc.


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                     IRREVOCABLE PROXY AND POWER OF ATTORNEY

         The undersigned appoints On-Site Sourcing, Inc. as the undersigned's
attorney-in fact and proxy, with full power of substitution, for and in the
undersigned's name, to in favor of any proposal presented to stockholders that
is reasonably necessary to consummate the Merger, including the amendment to the
U.S. Technologies Inc. Restated Certificate of Incorporation ("the Charter
Amendment"), and, if any separate vote occurs, the Merger (as defined in the
Merger Agreement), the adoption and approval of the Merger Agreement (without
any material changes thereto) and the approval of the transactions contemplated
by the thereby with respect to all of the shares of Common Stock, par value
$0.01 per share, of U.S. Technologies Inc., a Delaware corporation, owned of
record by the undersigned.

         The proxy granted hereby shall be irrevocable and may be exercised at
any meeting of stockholders at which the Charter Amendment or Merger Agreement
is considered, notice of which is given or in respect of any written consent
which is solicited prior to the due and proper termination of, and subject to
and in accordance with the terms and conditions of, the letter agreement, dated
of even date herewith, among the undersigned, U.S. Technologies Inc. and On-
Site Sourcing, Inc. This proxy is coupled with an interest sufficient in law to
support such proxy. This proxy shall terminate automatically and shall have no
further force or effect upon the consummation of the Merger or the termination
of the Merger Agreement, in each case in accordance with the terms of the Merger
Agreement.


Dated: September 27, 2000                    /s/ C. Gregory Earls
                                             -----------------------------------
                                             C. Gregory Earls


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                     IRREVOCABLE PROXY AND POWER OF ATTORNEY

         The undersigned appoints On-Site Sourcing, Inc. as the undersigned's
attorney-in fact and proxy, with full power of substitution, for and in the
undersigned's name, to in favor of any proposal presented to stockholders that
is reasonably necessary to consummate the Merger, including the amendment to the
U.S. Technologies Inc. Restated Certificate of Incorporation ("the Charter
Amendment"), and, if any separate vote occurs, the Merger (as defined in the
Merger Agreement), the adoption and approval of the Merger Agreement (without
any material changes thereto) and the approval of the transactions contemplated
by the thereby with respect to all of the shares of Common Stock, par value
$0.01 per share, of U.S. Technologies Inc., a Delaware corporation, owned of
record by the undersigned.

         The proxy granted hereby shall be irrevocable and may be exercised at
any meeting of stockholders at which the Charter Amendment or Merger Agreement
is considered, notice of which is given or in respect of any written consent
which is solicited prior to the due and proper termination of, and subject to
and in accordance with the terms and conditions of, the letter agreement, dated
of even date herewith, among the undersigned, U.S. Technologies Inc. and On-
Site Sourcing, Inc. This proxy is coupled with an interest sufficient in law to
support such proxy. This proxy shall terminate automatically and shall have no
further force or effect upon the consummation of the Merger or the termination
of the Merger Agreement, in each case in accordance with the terms of the Merger
Agreement.


Dated: September 27, 2000                    /s/ James V. Warren
                                             -----------------------------------
                                             James V. Warren


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                     IRREVOCABLE PROXY AND POWER OF ATTORNEY

         The undersigned appoints On-Site Sourcing, Inc. as the undersigned's
attorney-in fact and proxy, with full power of substitution, for and in the
undersigned's name, to in favor of any proposal presented to stockholders that
is reasonably necessary to consummate the Merger, including the amendment to the
U.S. Technologies Inc. Restated Certificate of Incorporation ("the Charter
Amendment"), and, if any separate vote occurs, the Merger (as defined in the
Merger Agreement), the adoption and approval of the Merger Agreement (without
any material changes thereto) and the approval of the transactions contemplated
by the thereby with respect to all of the shares of Common Stock, par value
$0.01 per share, of U.S. Technologies Inc., a Delaware corporation, owned of
record by the undersigned.

         The proxy granted hereby shall be irrevocable and may be exercised at
any meeting of stockholders at which the Charter Amendment or Merger Agreement
is considered, notice of which is given or in respect of any written consent
which is solicited prior to the due and proper termination of, and subject to
and in accordance with the terms and conditions of, the letter agreement, dated
of even date herewith, among the undersigned, U.S. Technologies Inc. and On-
Site Sourcing, Inc. This proxy is coupled with an interest sufficient in law to
support such proxy. This proxy shall terminate automatically and shall have no
further force or effect upon the consummation of the Merger or the termination
of the Merger Agreement, in each case in accordance with the terms of the Merger
Agreement.


Dated: September 27, 2000                    /s/ Jonathan Ledecky
                                             -----------------------------------
                                             Jonathan Ledecky


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                     IRREVOCABLE PROXY AND POWER OF ATTORNEY

         The undersigned appoints On-Site Sourcing, Inc. as the undersigned's
attorney-in fact and proxy, with full power of substitution, for and in the
undersigned's name, to in favor of any proposal presented to stockholders that
is reasonably necessary to consummate the Merger, including the amendment to the
U.S. Technologies Inc. Restated Certificate of Incorporation ("the Charter
Amendment"), and, if any separate vote occurs, the Merger (as defined in the
Merger Agreement), the adoption and approval of the Merger Agreement (without
any material changes thereto) and the approval of the transactions contemplated
by the thereby with respect to all of the shares of Common Stock, par value
$0.01 per share, of U.S. Technologies Inc., a Delaware corporation, owned of
record by the undersigned.

         The proxy granted hereby shall be irrevocable and may be exercised at
any meeting of stockholders at which the Charter Amendment or Merger Agreement
is considered, notice of which is given or in respect of any written consent
which is solicited prior to the due and proper termination of, and subject to
and in accordance with the terms and conditions of, the letter agreement, dated
of even date herewith, among the undersigned, U.S. Technologies Inc. and On-
Site Sourcing, Inc. This proxy is coupled with an interest sufficient in law to
support such proxy. This proxy shall terminate automatically and shall have no
further force or effect upon the consummation of the Merger or the termination
of the Merger Agreement, in each case in accordance with the terms of the Merger
Agreement.

Dated: September 27, 2000                    NORTHWOOD CAPITAL PARTNERS LLC


                                             By: /s/ Henry T. Wilson
                                                --------------------------------
                                             Name: Henry T. Wilson
                                             Title: Managing Director


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