Some places to go (paiseh, a little lazy to go dig out my stuff):
1) Alcatraz
2) Golden Gate Bridge
3) Palace of Fine Arts - absolutely stunning architecture
4) Lucasflim complex (just to go see see, there's the statue of Yoda there.. :bsmilie
It's near this park reserve, forgot the name. Warning though: the security guards are anal with photography on tripods.
5) Fisherman's Wharf, Pier 39
6) Musee Mechanique
http://www.museemechanique.org/ - near Fisherman's Wharf, interesting place, some of the really old mechanical entertainment boxes
7) Union Square (just to look see, and of course, visit the Apple store there)
8) Chinatown (quite near Union Square)
Pier 39 got quite some good stuff to eat. Try the mini doughnuts, Bubba Gump. I tried a seafood restaurant on the 1st level, food was OK though.
Try the crabs at fisherman's wharf -the experience's a good one. And to top if off, get some Ghirardelli chocolates home..
http://www.ghirardelli.com/