My loving little sister from Ft. Worth got this one in the e-mail and forwarded it to me. It seems to have been going around for awhile under the title "How to Tell if you Pi**ed off a Mathematician", and mostly, with a mis-answer for the amount. The copy my sister sent to me had this explanation for the check amount:

Unfortunatly, if you look closly at the amount, it is NOT e^{2 pi}, which would give the above amount (more or less). The exponent of e, as most mathematicians would expect, is in fact i * pi, where i is the imaginary constant. Leonhard Euler showed (although Cotes did a lot of the spade work for this) that e^{i pi} is actually equal to -1. It is often called the most beautiful theorem in mathematics, and it is certainly one of the more useful as it allows us to tie the real and complex values together. I used the theorem not too long ago in a blog I Don't Get It! about a tongue in cheek quote from De Morgan.

Using the correct expression, the check turns out to be written for $0.002, which is 2 mills, or two tenths of a cent. To me that makes the whole problem a little funnier and a little more interesting, but I'm not sure part of that is not a little intellectual snootieness (I get the joke and you probably won't); which I also spoke of not quite as recently Prime Time Fun.