Thor, I agree with your cooments. Two of my daughters live in SF, near the Presidio. They couldn't do it w/o help from me (rents are scary high).
I just came back from spending a few days with them. I do enjoy the bike culture (and the fact that people walk and/or use public transportation). It seems to me, from my largely exuburbian point of view, however, that SF is not an easy place to commute by bike. Traffic congestion, narrow streets and crazy drivers make it tough to bike in SF. But again, that's coming from a guy who rides mostly in open, rural areas and hills w/o much traffic.
For anyone visiting SF I recommend the Velo Rouge Cafe. The place is bike "themed." The coffee is FANTASTIC!
SF is a fun city, but living there takes a lot of planning ahead.