I saw this site link within an unrelated article http://housingmaps.com/
It links both the Google map site up with the www.craigslist.org site (Property rentals) and you can see by the Balloons and clicking on them ( and see the Ad off the Craigslist.org site) can alter the price range to suit your budget
Give it a go the sites Not been advertised yet
Is Limited to Mainland US at the moment and a few ads from Canada
Pass this on to your friends
Like to see this expand (looks a cracking idea)