Yesterday Google added Wikipedia to Google Maps, today they have added Real Estate. To display real estate for sale in your location choose the 'Show Search Options' link next to the 'Search Maps' button and then choose 'Real Estate' from the drop down menu (the two points underlined in red on the screen shot).
With the real estate layer turned on available houses and apartments will be tagged on the map and details of each property will be displayed in the left-hand side bar. When you click on a tag an information window opens displaying the price and image of the property. Clicking on the expand button or the 'more info' link will expand the information window and give you more details of the property.
The very first Google Maps mashup was created by Paul Rademacher. His mashup HousingMaps showed Craigslist housing listings on a Google Map. His hack of Google Maps inspired Google to open up Google Maps via the Google Maps API. Paul Rademacher now works for Google so he could well have been the inspiration for this new layer.
In other news Google have announced the latest image update for Google Earth. As always Google has announced the locations that are affected in the form of a quiz. Readers of the Google Earth Blog are normally amongst the first to find the right answers. Updates to Google Earth are usually added to Google Maps a week or two later.