If you're in the market for a home or a place to rent, you should check out this site, which uses craigslist and Google Maps to help you search for a home. This is what web services and open APIs are all about! Thanks to Paul Rademacher for this cool, useful tool:

http://www.paulrademacher.com/housing/

To start your search, begin with your choice of city (craigslist cities are what's represented, of course) and then you choose whether you are looking to buy or rent:

Next you can choose homes to view on the map, with the key information available in a list to the right. Yellow pointer icons mean the listing has pictures included. You can select your price ranges and you can sort based on price, description, location or date of listing:

(click for full-sized image)

Once you have found a place you are interested in finding out more about, click the home's pointer or the link in the list, and you'll see details, along with a link to the original complete listing.

(click for full-sized image)

Nice stuff. We can expect to see more and more of this sort of thing as time goes on and as services make their APIs more and more open and available to the public.