You will have seen the 'guess the dictator or sitcom character' expert system website. You pick a character from TV or film, answer a few yes/no questions and it guesses who you are. It learns from the users, and it's pretty good. I just added Bobby Goren - well, I answered all the questions right (I think) and it guessed I was Lennie Briscoe, so I added Bobby plus a deciding question. However, it's possible I got some of the earlier questions wrong.
A suggestion made by a commenter on douglain's blog was to answer the questions truthfully for yourself and thereby find out which character you are most like. What a great game!
Some of the questions were a bit tough - do I have a roommate - well, yes, the guy I sleep with, but that's probably not what it means. Still. If I was a girl I would be Rebecca from Cheers, and if I was a guy I would be Jeff from Coupling (yes, the horny Welsh git).