Every LA blogger and their mother has contributed a post about the UCLA photo archive: Changing Times: Los Angeles in Photographs, 1920-1990. Here's my obligatory contribution.
I read about the archive first at LA Observed: New toy for L.A. buffs, and I have admit that I've spent many hours searching for interesting photos. Every query has provided something interesting, and each query seems to lead down another fascinating path. The photos are licensed under the Creative Commons, so we're free to post images.
Here's one of Bing and his wife Kathy relaxing at Pebble (oddly, came up from a search for LAX).