I live in San Diego. Moved here about a year and a half ago and I still don't own a car. It's tought though. It's definitely a handicap for me in term of find jobs(I freelance as a graphic designer) because everything is spread out here in San Diego and the bus system here isn't the best. There's the commmuter train called the Coaster which I used almost every other day which is great, but the times are really limited to commuter hours and the weekend hours are almost nonexistant.
I'm actually thinking of moving somewhere more bicycle friendly and less car dominated. Portland, Oregon looks good, but it seems like it rains too much there. I haven't really found my niche here in S.D. yet.