THIS  OPTION  AND THE STOCK  ISSUABLE  UPON THE  EXERCISE  HEREOF  HAVE NOT BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"),  AND CAN BE
TRANSFERRED  ONLY IN COMPLIANCE  WITH THE ACT AND  APPLICABLE  STATE  SECURITIES
LAWS.  THIS OPTION AND SUCH SHARES MAY NOT BE SOLD,  TRANSFERRED  OR ASSIGNED IN
THE ABSENCE OF AN EFFECTIVE  REGISTRATION  STATEMENT,  UNLESS, IN THE OPINION OF
COUNSEL FOR THE COMPANY OR COUNSEL FOR THE REGISTERED  HOLDER (WHICH SHALL BE IN
FORM AND FROM SUCH COUNSEL AS SHALL BE REASONABLY  SATISFACTORY TO THE COMPANY),
SUCH REGISTRATION IS NOT THEN REQUIRED. NO REGISTRATION RIGHTS HAVE BEEN GRANTED
WITH RESPECT TO THIS OPTION AS OF ITS ORIGINAL DATE OF ISSUANCE.


                            U.S. WIRELESS DATA, INC.

                      NONQUALIFIED STOCK OPTION CERTIFICATE

     U.S. Wireless Data, Inc., a Colorado corporation ("Company"),  for good and
valuable consideration,  including the incentive to the Optionee to remain as an
employee of the Company as a result of ownership  or increased  ownership of the
Company's  no  par  value  common  stock  ("Common  Stock"),   the  receipt  and
sufficiency of which consideration hereby is acknowledged, irrevocably grants to
the Optionee the option ("Option") to purchase the following number of shares of
Common Stock:

       Optionee                              Number of Shares

       Rod L. Stambaugh                      600,000


The effective date of this grant is May 13,1999 ("Date of Grant") and is subject
to the following terms and conditions:

     1. EXERCISE  PRICE.  The purchase  price  ("Exercise  Price") for shares of
Common  Stock  purchasable  pursuant to this Option  shall be Zero and  813/1000
Dollars  ($0.813) per share,  which shall be paid in full in cash at the time of
exercise;  provided,  however, that the Board of Directors of the Company may in
its sole  discretion  permit  payment  to be made with  shares of the  Company's
Common  Stock owned by Optionee or shares  purchasable  by Optionee  pursuant to
exercise  of this  Option  in such a  manner  that  Optionee  shall  not have to
surrender any cash to exercise this Option (a "Cashless Exercise"). The Exercise
Price  represents the fair market price of the Company's  Common Stock as of the
date this  Option is  granted.  Optionee  shall have no rights  with  respect to
dividends  or have any other  rights as a  shareholder  with  respect  to shares
subject to this Option until  Optionee has given written  notice of the exercise
of the Option and has paid in full for such shares.

     2. VESTING AND TIME OF  EXERCISE.  This Option will vest 50% upon the grant
date  and one  twelfth  (1/12)  per  month  at the end of  each  monthly  period
following  grant date.  This Option may be exercised as to all or any portion of
the vested shares covered by this Option Grant, and shall expire on the later of
ten years from the grant date,  or one year after  cessation of the  Executive's
relationship with the Company in any capacity, including service provided to the
Company as an  employee,  officer,  director or  consultant.  The period of time
during  which the Option may be  exercised  is referred to herein as the "Option
Period."

     3.  NUMBER  OF  SHARES  PURCHASABLE  AT ANY ONE TIME.  This  Option  may be
exercised only for at least 100 shares of Common Stock or a multiple  thereof or
for the full number of shares for which the Option is then exercisable.

     4. DEATH OF OPTIONEE.  If Optionee dies during  Optionee's  employment with
the  Company,  this  Option  shall  be  exercisable  only  as  to  that  portion
exercisable as of the date of death and within one year after Optionee's  death,
or the last day of the Option  Period,  whichever  is earlier,  by the  personal
representative or administrator of Optionee's  estate, or by any trustee,  heir,
legatee or beneficiary to whom Optionee's rights under this Option shall pass by
will or the laws of descent and  distribution  to the extent that  Optionee  was
entitled to exercise this Option at the time of Optionee's death.


<PAGE>


     5.  RETIREMENT  OF  OPTIONEE.  If  Optionee's  employment  with the Company
terminates by reason of retirement,  the Option shall be exercisable  within the
one year period  following  Optionee's  retirement as described  above,  but not
later  than the last day of the  Option  Period,  and then only to the extent to
which the Option was  exercisable at the time of such  termination of employment
by retirement.  However,  if Optionee dies within three months after termination
by  retirement,  the  Option,  to the extent it was  exercisable  at the time of
Optionee's death, shall thereafter be exercisable for one year after the date of
Optionee's death, but not later than the last day of the Option Period.

     6.  DISABILITY OF OPTIONEE.  If Optionee  becomes  permanently  and totally
disabled,  and at the time of such  disability  Optionee is entitled to exercise
one or more  installments  under this Option,  Optionee  shall have the right to
exercise this Option  within one year after such  disability  provided  Optionee
exercises  this Option  within the Option  Period and then only to the extent to
which this Option was exercisable at the time of such  disability.  For purposes
of this Section 7 an Optionee shall be considered to be totally and  permanently
disabled if a qualified medical  physician  approved by the Company certifies to
the Company that such Optionee is unable to be gainfully employed by the Company
by reason of a diagnosed and  determinable  physical or mental  impairment which
can be expected to result in death or has lasted and can be expected to last for
a continuous period of not less than 12 months.

     7.  NONTRANSFERABILITY  OF OPTION.  This Option may not be  transferred  by
Optionee otherwise than by will or the laws of descent and distribution.  During
Optionee's lifetime, this Option shall be exercisable only by Optionee.

     8. LEAVE OF ABSENCE.  For purposes of this Option,  (i) a leave of absence,
duly authorized in writing by the Company, for military service or sickness,  or
for any other purpose approved by the Company,  if the period of such leave does
not  exceed 90 days,  and (ii) a leave of  absence  in  excess of 90 days,  duly
authorized in writing by the Company,  provided Optionee's right to reemployment
is  guaranteed  either  by  statute  or by  contract,  shall  not  be  deemed  a
termination of employment.

     9. CHANGES IN CAPITAL; CERTAIN  REORGANIZATIONS.  If the outstanding Common
Stock  of the  Company  which is  subject  to this  Option  shall at any time be
changed or exchanged by declaration of a stock dividend,  split-up,  subdivision
or  combination  of shares,  recapitalization,  merger,  consolidation  or other
corporate reorganization in which the Company is the surviving corporation,  the
number of and kind of shares subject to the Option and the Option Price shall be
appropriately and equitably adjusted so as to maintain the proportionate  number
of  shares  without  changing  the  aggregate  option  price.  In the event of a
dissolution or liquidation of the Company, or a merger,  consolidation,  sale of
all or substantially  all of its assets,  or other corporate  reorganization  in
which the Company is not the surviving  corporation,  or in which the Company is
the  surviving  corporation  but holders of Common Stock  receive  securities of
another  corporation,  this Option shall  terminate as of the effective  date of
such event,  provided that immediately prior to such event,  Optionee shall have
the right to  exercise  this  Option as to all shares  underlying  this  Option,
irrespective of the number of Options actually vested at the time.

                                       2
<PAGE>

     10. MANNER OF EXERCISE.

          (a) This Option may be  exercised  in whole or in part at any time and
from time to time within the Option Period,  subject to the terms and conditions
contained  herein,  by the  delivery of written  notice of exercise to the Chief
Financial Officer of the Company,  as required by subsection (c) of this Section
11,  accompanied  by: (i) full  payment,  in cash or  certified  or bank  check,
payable  to the  Company,  or,  (ii) if  permitted  by the  Company's  Board  of
Directors, shares of the Company's Common Stock having a fair market value equal
to the aggregate exercise price for the number of shares purchased.  This Option
may also be exercised by "cashless exercise," as described below.

          (b)  Certificates  for the  shares  of  Common  Stock  purchased  upon
exercise  of this Option  shall be  delivered  by the  Company to the  Purchaser
within five (5) business days after the Exercise Date. However, if the Purchaser
has  elected  to  make  a  "cashless   exercise,"   the  Company  shall  deliver
certificates  for the number of shares that results from  subtracting,  from the
total number of shares otherwise deliverable upon exercise, the number of shares
whose value,  calculated  using the Market  Price,  is equal to the value of the
payment otherwise  required for exercise by Paragraph (a)(iv) of this Subsection
2.2.  For  purposes of this  section,  "Market  Price"  means the average of the
closing prices of sales on the principal domestic  securities  exchange on which
such security may at the time be listed,  or, if there have been no sales on any
such exchange on any day, the average of the highest bid and lowest asked prices
on all such exchanges at the end of such day, or, if on any day such security is
not so listed,  the average of the bid and asked  prices  quoted on Nasdaq as of
the close of  trading in New York City on such day,  in each such case  averaged
over a period  of five (5)  consecutive  days  consisting  of the  business  day
immediately  preceding the day as of which Market Price is being  determined and
the four (4) consecutive  business days prior to such day; provided that if such
security is listed on any principal  domestic  securities  exchange or quoted on
Nasdaq,  the terms  "business  day" and "business  days" means a day or days, as
applicable,  on which such  exchange or Nasdaq is open for trading or quotation,
as the case may be,  notwithstanding  whether any  quotation is available on any
particular  business day and, if not,  then the Market Price shall be determined
based upon those  remaining  days during the  aforesaid  5-day  period for which
quotations  are  available.  If the  shares  are not so  listed or traded on any
principal  domestic  securities  exchange or quoted on Nasdaq,  the Market Price
shall be the fair value  thereof,  as  determined  in good faith by the Board of
Directors of the Company.

          (c) The notice of exercise  (i) shall  state the  election to exercise
the Option, (ii) shall state the number of shares in respect to which the Option
is being  exercised,  (iii) shall  state  Optionee's  address,  (iv) shall state
Optionee's social security number,  (v) shall contain such  representations  and
agreements  concerning  Optionee's investment intent with respect to such shares
of Common Stock as shall be  satisfactory  to the  Company's  counsel,  and (vi)
shall be signed by  Optionee.  As a further  condition  to the  exercise of this
Option, the Company may require Optionee to make any representation and warranty
to the Company as may be required by any applicable law or regulation.

          (d) Unless  this  Option has  expired  or all of the  purchase  rights
represented  hereby  have been  exercised,  the  Company  shall,  in addition to
certificates for Common Stock issued upon exercise of this Option,  prepare upon
exercise  of  this  Option,  a  new  Option  representing  the  rights  formerly
represented by this Option that have not expired or been exercised.  The Company
shall,  within five (5) business days after the Exercise Date,  deliver such new
Option to the Optionee designated for delivery in the Exercise Agreement.

                                       3
<PAGE>

     11.  AMENDMENT AND  ADMINISTRATION.  The Board of Directors  shall have the
authority  to  interpret  the Plan this  Option,  and  generally  to conduct and
administer  the  exercise  of this  Option  and to make  all  determinations  in
connection herewith which may be necessary or advisable, and all such actions of
the Board  shall be final and  conclusive  for all  purposes  and  binding  upon
Optionee.

     12. MISCELLANEOUS. This Option shall inure to the benefit of and be binding
upon each successor of the Company.  All obligations imposed upon and all rights
granted to the Optionee and all rights reserved by the Company under this Option
shall be binding  upon and inure to the benefit of Optionee,  Optionee's  heirs,
personal  representatives,  administrators  and  successors.  Unless the context
requires otherwise, words denoting the singular may be construed as denoting the
plural,  and words of the plural may be  construed  as denoting the singular and
words of one  gender  my be  construed  as  denoting  such  other  gender  as is
appropriate.

     IN WITNESS WHEREOF, this Option has been issued by the Company effective as
of the Date of Grant, which is May 13, 1999.


U.S. WIRELESS DATA, INC.                       Accepted by Optionee:
a Colorado corporation


/s/ Dean M. Leavitt                            /s/ Rod L. Stambaugh
    ------------------------                   -------------------------
    Dean M. Leavitt                               Rod L. Stambaugh
    Chief Executive Officer

Attest:


/s/ Robert E. Robichaud
    --------------------------
    Robert E. Robichaud
    Secretary