Got an area shop recommendation, but it's not exactly in San Diego. Head up the coast a ways to Solana Beach and hit up Bike 101. They don't stock a great deal of SS/Fixed stuff 'cause there's not a huge market for it around those parts, but most of 'em ride fixed/ss and they'd probably at least have a few track cogs, and SS freewheels in stock, and probably a SS mtb or two on the showroom floor. Dunno if they usually carry track-bikes, or if that's more of a special-order thing.

Dan, the manager, is a riding buddy of mine from way back, and a singlespeed mtn. biker who also races cross and rides fixed on the road. Tony, one of the mechanics is also a SS'er and an all around good guy (Not to mention, effin' strong. He won the Worlds Solo 24 Hr. championship singlespeed division last year, and also won the 12-hours at Summit solo-singlespeed class.), and the buyer Jeff is an ex-messer and fixie afficianado. Show up to one of the Friday morning road-rides and there's likely to be a fixie or two in the bunch.

-Trevor