Exhibit 10.1

PROMISSORY NOTE

$100,000.00 Dated: November 5, 2007

        FOR VALUE RECEIVED, the undersigned, Protexx, Inc. and its subsidiaries,
including but not limited to 22THEN LLC (collectively, the “Borrower”), HEREBY
PROMISES TO PAY to the order of WidePoint Corporation (the “Lender”) UPON DEMAND
on an Event of Default as further defined in the Revolving Line of Credit
Agreement or upon Final Maturity (as hereinafter defined) the principal sum of
One Hundred Thousand Dollars ($100,000.00) or, if less, the aggregate principal
amount of the advances made by Lender to Borrower (each, an “Advance”), with
such payment being guaranteed by Peter Letizia, individually (“Guarantor”),
pursuant to that certain Revolving Line of Credit Agreement, dated as of
November 5, 2007, between Borrower and Lender (as amended or modified from time
to time, the “Credit Agreement”) (capitalized terms defined therein and not
otherwise defined herein being used herein are therein defined).

        Borrower and Guarantor promise to pay interest on the unpaid principal
amount of each Advance from the date of such Advance until such principal amount
is paid in full, at such interest rates, and payable at such times, as are
specified in the Credit Agreement.

        Both principal and interest are payable in lawful money of the United
States of America to the Lender, at its office located at One Lincoln Center,
R.E., Suite 1100, Oakbrook Terrace, Illinois, 60181, or at such other address as
the Lender may specify in writing from time to time, in same-day funds. Each
Advance owing to Lender by Borrower and Guarantor pursuant to the Credit
Agreement, and all payments made on account of principal thereof, shall be
recorded by Lender and, prior to any transfer hereof, endorsed on the grid
attached hereto, which is part of this Promissory Note.

        This Promissory Note is the Promissory Note referred to in, and is
entitled to the benefits of, the Credit Agreement and secured by a Security
Agreement also referred to in the Credit Agreement. The Credit Agreement, among
other things, (a) provides for the making of Advances by the Lender to the
Borrower from time to time in an aggregate amount not to exceed at any time
outstanding the U.S. dollar amount first above-mentioned, the indebtedness of
the Borrower and Guarantor resulting from each such Advance being evidenced by
this Promissory Note, and (b) contains provisions for acceleration of the
maturity hereof upon the happening of certain stated events and also prepayments
on account of principal hereof prior to the maturity hereof upon the terms and
conditions therein specified.

[The next page is the signature page.]

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        IN WITNESS WHEREOF, each of the Borrower and Guarantor has caused its
duly authorized officer to sign and deliver this Promissory Note with the intent
to be legally bound hereby, as of November 2, 2007.

WITNESS: PROTEXX, INC.

/s/ Bruce Nachman By:  /s/ Peter Letizia Name:  Bruce Nachman Name:  Peter
Letizia Title:  CEO/President

WITNESS: 22THEN LLC

/s/ Bruce Nachman By:  /s/ Peter Letizia Name:  Bruce Nachman Name:  Peter
Letizia Title:  CEO/President

WITNESS: GUARANTOR

/s/ Bruce Nachman /s/ Peter Letizia Name:  Bruce Nachman Peter Letizia,
Individually

Acknowledged and Accepted:

WIDEPOINT CORPORATION

By:  /s/ James McCubbin
Name:  James McCubbin
Title:  V.P. and C.F.O.

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ADVANCES AND PAYMENTS OF PRINCIPAL

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Date

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Amount of
Advance

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Amount of
Principal Paid
or Prepaid

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Unpaid Principal
Balance

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Notation
Made By

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