http://paulrademacher.com/housing/ACK this is cool. So cool I want to punch myself. Yes, I've seen RedFin which is also very cool, but the fantastic thing about this is that it combines a totally user driven ad system (Craig's List) with a totally open map system (Google Maps) and gives you more information than just looking at each individually. To quote the mailing list I saw this on, it probably breaks Google's Terms of Service, but if they block this (and other functionality which is coming), they're making a big mistake. Just think, if you could have all real estate activity pushed through RSS you could subscribe and paint entire sections of maps with MULTIPLE sources! Then you could say what was hot, what was cold, who is moving where... it'd just be fantastic!D