I was in Balboa Park this evening just as darkness descended, and from about 200 years away I could suddenly see flashing lights over by our famous fountain. Looked a bit like police car lights, but not quite. I began walking that way when it became clear there were about 200 folks on bikes, with blinkies and all sorts of other lights getting ready for an urban night ride. Soon enough they set out, swooping and riding round and round the fountain, and then down the main thoroughfaire (which does not allow automobiles). I was sooooooooooooooooooooooooo envious!
If there's anyone reading this from San Diego who knows what the heck this was, please tell me. If it's a regular event, I'd like to join in if that's possible.