While Google Maps is a very popular and suitable tool for most kinds of real estate listings, the 3D features in Google Earth can be very useful to visualize real estate inside of tall buildings. Cube Cities does an amazing job of that, by clearly highlighting the location of their properties with obvious markings on the face of the 3D building itself. It’s quite effective.
Clicking on red area then provides you with details about that listing, as seen here.
It uses the Google Earth API to display the buildings, then overlays them with various colored polygons to indicate the available space. It’s an excellent use of Google Earth and has been put together very well.
Check it out for yourself at CubeCities.com.
(via Google Maps Mania)