Nonprofit Technology Network (NTEN) Drupal Group

Mailing list: http://groups.nten.org/group.htm?mode=home&igid=90979

Drupal For Good - San Francisco Bay Area

A Bay Area-based community of practice for 'social tech' people learning/using Drupal.
Mailing list: http://groups.google.com/group/drupalforgoodSFBA

South Bay Drupal Users Group

Website: http://groups.drupal.org/south-bay-california
Meetups: http://www.meetup.com/DrupalGroup/
LinkedIn: http://www.linkedin.com/groups?gid=122306

SF Drupal Users Group

Website: http://groups.drupal.org/bay-area

Berkeley Drupal Users Group

Website: http://groups.drupal.org/berkeley
Mailing list: http://groups.google.com/group/berkeley-drupal?hl=en

Santa Cruz Drupal Users Group

Website: http://groups.drupal.org/santa-cruz