"Craigslist has tons of listings for apartments, houses, and rooms but it's not particularly convenient to click each listing and then cross-reference it to a map. HousingMaps combines Craigslist listings with Google Maps to make it easy to pinpoint locations.
HousingMaps searches apartments, condos, houses, and rooms for rent, as well as homes and condos for sale and subletting offers. You can narrow your search to most of the markets served by Craigslist and by price range. Additional filters allow you to search by keyword, number of rooms, pet policy, and whether or not the listing has pictures.
Search results are displayed on a map of the city and listed to the right of the map. The columns in the listing chart can be ordered ascending or descending by the various categories like price, number of rooms, and so on. It's a pretty great service when it works, and was mentioned in passing in our roundup of the top 10 real estate search tools. In passing because, like anything hooked into Craigslist's data, occasional push-back from the classifieds site can leave sites like HousingMaps high and dry, at least for a time.
HousingMaps is a free service and requires no signup."
When I find stuff like this it makes surfing through all those RSS feeds I have worth it.