Google has stealthily added a new housing search feature when the query term relates to Housing. It seems like it is a hybrid of Google Base listings as well as some naturally indexed property listings sites. Google, please – just tweak your map search so it has view based refresh and you will topple the industry!

http://digg.com/technology/Google_Enters_Real_Estate_Vertical_Search

http://www.google.com/search?q=san+francisco+real+estate