www.aczadance.org should get you started.

www.wle.netfirms.com/zt-news.htm

wle.

I would check the Bon Temps Social Club calendar.
http://dances.com/casd/bonstemps/calendar_0406.htm

Or check Zydeco Brad's page. (LA is only a couple of hours drive from San Diego.)
http://members.aol.com/zydecobrad/zydeco.html

If you come in on the weekend, you will be able to catch Dexter Ardoin on the 8th in San Diego or 9th in Gardena.

Or for local bands, check out
the San Diego Cajun Playboys. http://www.cajunnetwork.com/sdcp/

or Bonne Musique Zydeco
http://www.bonnemusiquezydeco.com/

Or Zydeco Patrol
http://www.zydecopatrol.com/

Good luck,
DP