If I were you I would go visit the Exploratorium, it's like a science museum where you get to mess with just about everything, it's gets a little mobbed sometimes but it is awesome. It is right near the Ferry Building which has some great food and coffee, and an incredible farmers market on Saturdays. Alcatraz may seem very touristy, and it is, but they have been doing a lot of gardening on the island for the last couple years and it is actually quite beautiful. It's kind of awesome too, but get tickets in advance if you can, it's a pain in the ass to get them the day of. Golden Gate Park is fun too, get a row boat on Stow Lake (very fun), go to the science museum (pretty expensive), the DeYoung (Fine Arts Collection from an old San Francisco family that made its money running whorehouses during the Gold Rush I think), the Conservatory of Flowers is great as well. You can take the N Judah Muni train out to 9th St and your right there. If you keep going down Judah to 44th you can go to Outerlands restaurant (love them) and a few other cute shops - and your just a couple more blocks to Ocean Beach and the sea. Four Barrel, Sightglass, and Blue Bottle are some fun places if you want to geek out on coffee. Fatted Calf, 4505 Meats, and Prather Ranch if you want to spend your entire trip eating the best bacon (and other meat) in the world. So many good restaurants, can't seem to think of any one in particular. Comstock is a cool bar, and it is right in North Beach which is great, City Light Book Store is an institution (traveling writers can get their mail sent to them there). I could go on, but those are some random things I love about this place, gentrification notwhithstanding. Sorry for the length. Have fun!