Fun family things to do in San Francisco?

I'm going on vacation with my dad and 12 year old brother (I'm 17) soon to San Francisco. None of us have been there before so we wanted to check out the cool things they have to do there. Unfortunately we have no idea what there is there besides the Golden Gate Bridge and a Ripley's Believe it or Not museum. Do you have any ideas on fun family activities?Fun family things to do in San Francisco?
all of the above.

Make reservations on most spots like Alcatraz, far in advance, etc...

check it out first.Fun family things to do in San Francisco?
1. Alcatraz

2. Get on a cable car at Powell St.

3. The Ferry Building

4. Coit Tower and North Beach

5. Union Square

6. Golden Gate Park and the new Academy of Sciences

7. Take the ferry to Sausalito

8. Fisherman's Wharf (tacky but everyone does it) - best thing there is the sealions

9. Do "the hills" (Lombard St, etc.)Fun family things to do in San Francisco?
Chinatown

fisherman's wharf/pier 39

ride a cable car (it goes through many cool places)

crookedest street

alamo square

market street (shopping!)

ExploritoriumFun family things to do in San Francisco?
check this for family, outdoor and fun activities in SF:

http://www.vacationopedia.com/sanfrancis鈥?/a>
Chinatown

Nob Hill