The City and County of San Francisco has a new open data site:
Please follow the link to the site to search, browse and view San Francisco data.

Description: The San Francisco Public Utilities Commission (SFPUC) is undertaking a major water system improvement program to repair and improve the Hetch Hetchy water delivery system. The SFPUC will let construction contracts valuing $2.3 billion, between now and 2013.
Agency Name: San Francisco Public Utilities Commission
Date Released: Periodic
Time Period: 2007-Current
Frequency: Periodic
Location of dataset:

DataSF is a clearinghouse of datasets available from the City & County of San Francisco. Our goal in releasing this site is:
(1) improve access to data
(2) help our community create innovative apps
(3) understand what datasets you'd like to see
(4) get feedback on the quality of our datasets.