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 e2 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 ei 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.