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 McCubbinTitle:  V.P. and C.F.O.

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ADVANCES AND
PAYMENTS OF PRINCIPAL

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