You may also want to consider a Muni passport (http://www.sfmuni.com/cms/mms/fares/...htm#passports). For 7 days, it's US$20 and includes all busses, cable cars, muni trains, and street cars. (These are also available with some of the discounts at http://www.sfcvb.org/.)

You can pick these up at most hotel news-stands or at the Convention & Visitors Bureau at Powell and Market.

Have a great trip!

Bob