I heard about a new Google service (might still be in Labs) relating to property rentals and purchase whereby a user keys in say "properties in xyz suburb" and Google spits out SPECIFIC properties that have been uploaded by property agents. Not just websites with properties.
I cannot find anything about it now - maybe I was dreaming :)
Google doesn't make it easy to find. They also seem to be returning listings from various local real estate directories in Google Maps, perhaps because not enough people have been able to find Google Base.
A real estate search box is returned out the top of the regular serps pages for some real estate searches and not others.