Passed by this website a few weeks ago. Although I no longer ride fixed gears, nor am I hip - it's still a really fun way to design some ridiculous looking bikes. I spent some time on it and I actually made a jersey design that I'll be wearing this year when I race.

http://www.pedalmafia.com/mafid/mafia_id.html

for some truly utterly ridiculously stupid designs that some of my buddies and i did, check this site:
http://ridefetish.com/blog/1124/thep...---all-welcome