A Craigslist-Gmaps mashup for apartment hunting.
This used to be hosted here: http://www.cs.berkeley.edu/~shaddi/housing/, but I've not had time to maintain it.
It was from a time before Craigslist had a map view on their site, so it's less useful now. Unsure if it still works given recent changes in Craigslist's layout, but feel free to submit patches if you get it working.