San Francisco is California's fourth largest city behind LA (1), San Diego (2) and Sacramento (3).
Mr. Mojo had it right in post 14.
From the World Almanac, 2003:
LA 3,819,951
SD 1,266,753
San Jose 898,3439
SF 751,682
Long Beach 475,460
Fresno 451,455
Sacramento 445,335
Oakland 398,844
Sacramento is the capital, yet 7th in population.