In the link below, John Hargrave goes to great lengths in an attempt to get his credit card receipt signature rejected.  Unfortunately, he is unsuccessful; but the many and varied attempts sure crack me up!  I particularly liked this line:

“The waitress at the restaurant didn't say anything, probably because I am mistaken for Mariah Carey all the time. Except for the goatee and the back hair, we are like twins.”

http://www.zug.com/pranks/credit/index.html