Google has expanded again, this time moving into the world of real estate--or at least real estate listing services. Their website, called Google Base, launched in November 2005, and lists properties for sale, which can be uploaded free. Home buyers can narrow their search by typing in particular areas, such as "San Francisco real estate."

Although the information isn't nearly as complete as the typical MLS listing, the new Google service allows buyers the opportunity to search with more anonymity than most similar sites. Before Google Base, viewers were generally asked to reveal personal information before they were given a chance to look at properties, and that information was then used as leads for agents.

It's a free advertising vehicle for agents, similar to Realtor.com, but doesn't offer nearly the choices of the actual MLS. However, the site has been up and running for less than a year, so it's yet to be determined what the site will eventually look like, in terms of the number of properties and the site