A fair number of Google employees live in the city and commute to their Mountain View campus daily. You may have seen the legions of Google shuttles around the city. More information on the Google shuttle program. Google also has a San Francisco office in the Financial District on Spear street.
Some shuttle drop off points
Relevant SF-Google links
- Google's gentrification shuttle: The counter-migration has begun — feature piece in the San Francisco Bay Guardian
See also yupster.