yep, i ride fixed tho' i've mostly been on the road bike lately as i'm trying to get better at climbing.
there are a quite a few fixies around sjsu/downtown, and a few other south bay fixed riders on BF.
check for ride flyers/postings at Good Karma downtown (myspace.com/goodkarmasj). i am more of a bad-weather commuter fixie nerd myself so i don't do too much of the nighttime hipster bar-crawl + bike ride thing but i can see the appeal