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                                                                     EXHIBIT 5.1


                   [Letterhead of Fulbright & Jaworski L.L.P.]


April 17, 2000


Cambio, Inc.
6006 North Mesa Street
El Paso, Texas 79912

Ladies and Gentlemen:

     We refer to the Registration Statement on Form S-8 (the "Registration
Statement") to be filed with the Securities and Exchange Commission under the
Securities Act of 1933, as amended (the "Act"), on behalf of Cambio, Inc. (the
"Company"), relating to an aggregate of 5,000,000 shares of the Company's Common
Stock, $.01 par value per share (the "Shares"), to be issued under the Cambio,
Inc. 2000 Stock Plan (the "Plan").

     As counsel for the Company, we have examined such corporate records, other
documents, and such questions of law as we have considered necessary or
appropriate for the purposes of this opinion and, upon the basis of such
examination, advise you that in our opinion, all necessary corporate proceedings
by the Company have been duly taken to authorize the issuance of the Shares
pursuant to the Plan and that the Shares being registered pursuant to the
Registration Statement, when issued and paid for under the Plan in accordance
with the terms of the Plan, will be duly authorized, validly issued, fully paid
and non-assessable.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement. This consent is not to be construed as an admission that
we are a person whose consent is required to be filed with the Registration
Statement under the provisions of the Act.

                                       Very truly yours,



                                       /s/ FULBRIGHT & JAWORSKI L.L.P.