What are some fun things to do in San Francisco that isn't costly?

Me and my boyfriend are going to SF and it is so hard to figure out what we could do. Do you know some places like operas, plays, hip hop clubs. Or anything?What are some fun things to do in San Francisco that isn't costly?
http://sf.funcheap.com/What are some fun things to do in San Francisco that isn't costly?
hang out in Crisy Field, walk aroun Fishermans Warf, Cruise the Castro%26gt; chech out whats on San Francisco
Definitely go to Alcatraz island. Its $24.50, and an absolutely fantastic day out. If you want something free you could take a walk over the golden gate bridge, have a wander about fisherman's wharf or go check out Lombard street, between hyde and leavenworth streets, its the most crooked street in the world apparently!What are some fun things to do in San Francisco that isn't costly?
Fishermans Wharf is fun to walk around and you'll probably see Sea Lions. And while you're there you can get tickets to get on a sight seeing boat that takes you to Alctraz for a walking tour.
go to the world class zoo, take a trolley, walk around Chinatown, go to Ghirardelli Square and Fisherman's Wharf- have a crab or shrimp cocktail!- visit Golden Gate Park and go to the museum/planetarium and Japanese Tea garden there..... ther is SO much to do and much of it inexpensive or free. Have a great trip- it's the city where I was born and always beautiful!What are some fun things to do in San Francisco that isn't costly?
take a tour of pac bell park. THe tour is free (last I checked) with a reservation and it is an excellent tour (I am not into baseball but I really enjoyed the tour).



Also there is a nickel arcade at fisherman's wharf that is fun.
Check on Craigslist.org SF BAY AREA for Events. They have a bunch you will like. A lot of free comedy clubs too.
Stern Grove:

http://www.sterngrove.org/2008season.htm鈥?/a>