I am a former resident of the Bay Area (since moved to SoCal) and there is a group dedicated to SFO
spotters. The website is http://groups.google.com/group/sfo-spotters?hl=en
and its a pretty good site run by real nice people who will gladly set up a spotting time.
As for sites around or near SFO
, I like the fishing pier near Coyote Point Park as well as Coyote Point Park. This particular location is about 1.5--2 miles from runway 28L/R so you can get nice shots of every airline and airliner coming into SFO
Also about the caltrain station place, just down the road is "Lions Park" where there is a parking lot near the baseball field where you can get even better departure shots without risking the plane being in between power lines.
if you have any more questions or would like to see some samples of mine from these locations my e-mail is firstname.lastname@example.org and I will gladly show you them!
Also, if the weather is bad, then there might be a chance of getting arrivals on the 10's which means they fly right over the TanForan shopping center in San Bruno which makes for unique shots!!