SF's full of great moviegoing, actually.
Right now, the San Francisco International Film Fesitval is going on at the Kabuki Sundance Cinemas in Japantown. Details here:
http://fest09.sffs.org/
Depending how long you're in town, you can also see virtually every currently buzzing indie at places like the Lumiere at California and Polk, the Opera Plaza multi, the Roxie in The Mission, or The Bridge on Geary (
Anvil opened there today). Currently, the Landmark on Fillmore is doing a midnight showing of
Metropolis with live music.
The Cartoon Art Museum on Mission (not far from the Metreon) is a fun little side trip. Right now, they have exhibits on Stan Sakai (creator of
Usagi Yojimbo), as well as a display of props and costumes from the
Watchmen film.
As someone else mentioned, there's great music/movie shopping at stores like Amoeba and Rasputin's (which is just off Union Square, near the cable-car turnaround).
Great eats for not too much dough include Dottie's True Blue Cafe on Jones Street, near Geary (allow for a lengthy wait, but the food is worth it, particularly if you like traditional breakfast fare), and Big Nate's BBQ on Folsom (that's NBA Hall of Famer Big Nate Thurmond).
If you're still going to be here next weekend, May 3rd will be the first of 2009's Dashiell Hammett tours of San Francisco, with local author Don Herron taking you through key locations featured in Hammett's hard-boiled detective fiction:
http://www.donherron.com/tour.html
And today's SF Chronicle has a feature on finding famous Bay Area movie locations. It's on the back page of the Datebook section, or you can find it
here.
And finally, here's a fascinating landmark for you: a couple years ago, the long-disused San Francisco Armory building in The Mission (I understand a couple of scenes from the original
Star Wars were shot there) was bought out by a British fetish porn entrepreneur, so there is now a massive porn film studio situated in a huge castle in downtown S.F that's worth a walkby and looksee. I sort of doubt they give tours, but I do know they have plans to turn the outside areas into some kind of community cultural arts hub. You can read more and see (unfortunately SFW) pix
here.