[nkurz]

You'll probably get better answers, but I'll start since no one has who's actually living car free has chimed in.

I think San Francisco proper and Berkeley are probably the only places where living without a car is a respected choice. There are certainly people who do so elsewhere around the Bay, but I get the sense that they aren't as thrilled about it. I'm inland in the East Bay, and most here would consider a car a necessity.

Overall, judging by the standards of major cities in other countries, the public transportation isn't great. It exists, it's much better than the heartland of the US, and for certain routes is very convenient, but it won't get you everywhere you want when you want it. You'll probably also want a bicycle, friends with cars, or even a Zipcar membership.

It would help to know where you are moving from, as that might affect your expectations considerably.