We already knew that Google Maps was amazingly useful (see Create walking directions with Google Maps
, or Ten Great Google Maps Resources
), but with the ability to actually search real estate listings within Google Maps' deep geographical indexes, the useful factor just got knocked up about ten notches. You can use Google Maps to search for houses on the market, houses that have been recently sold, explore the neighborhood, see the home in street view mode, see houses in foreclosure, see houses for rent, etc.
You can narrow your searches pretty easily, too; just click the "Show Options" link in the left-hand column of your search results and you can filter by bedroom, bathroom, listing type, and square footage. Caution: this can get pretty addicting!
More about Google Maps and real estate on the Web