HousingMapsHousingMaps was the very first Google Maps mashup, created before there was a Google Maps API. It overlaid Craigslist apartment and housing listings on a map, for some 30 US cities plus London. When it launched, in popularized the idea that real estate was best browsed on a map -- before that, real estate sites only showed lists of properties! It also introduced the idea that you can build a new w
