Here’s a web forum on pirate radio in San Diego.
I myself live near downtown, and I’ve listened to 96.9 here in town — they have an official site , though they sometimes play good music, they’re juvenile. Still, I have a bit of political sympathy for making spectrum free where it does not interfere with licensed stations. I like independent media.
Related: you can see SDRadio.net for current local radio news.
And Radio-Locator.com has a really cool feature where you can see the shape of the signal of radio stations. Here’s a search in San Diego: City College’s KSDS Jazz station, here’s 94.9 and here’s KGB, to pick a few at random. Strangely, they don’t seem to have stations based in Mexico, but which target San Diego, e.g XTRA-FM, 91X.