Looks like the Lights Out SF event last night was a big success. Here are some photos. Above, the Golden Gate Bridge, before and then during the event, which encouraged people (and municipalities) to turn off their lights for an hour as an exercise in power consumption awareness.
Organizer/spokeshottie Nathan Tyler is a former Google PR rep, and Google "turned out the lights" for Bay Area users for an hour. Incidentally, when Nate suggests people "party in the dark" as an eco-lifestyle action — have dinner parties with no lights on, for example — coming from him, it doesn't sound like a bad idea.
The group also encourages people to swap at least one bulb in their home or office to compact fluorescent bulbs, which can help reduce your overall electricity use.