Well, I tried the free house listing service on Google http://base.google.com/base/help/realestate.html and it looks pretty slick. I did a search for homes on the web search, and a home on their listing did show up, but not their handy search site that seems hard to come across: http://www.google.com/base/s2?a_n0=housing&a_y0=9&hl=en&gl=US

But realistically, it does no good for Google to show the special housing search site until the database is populated with a whole lot more listings.