"Fly" Around High-Rise Buildings... Check out the image below of downtown Chicago, looking northwest from a height of 3,600 feet. If you were viewing this image at Google Earth, you could "fly" through all of downtown Chicago, reduce your altitude, tilt your view, change direction -- whatever you'd like. 
It's amazing. You'll find 3D images for major downtowns across the U.S. from New York to Dallas to San Francisco. Google has added the shapes of thousands of buildings to
its free service. How did
they do this?
Download and install the program at Google Earth. Takes a couple of minutes. Search for a city, say,
Boston, MA. As you zoom into Dallas, notice the altitude dropping in the lower right-hand corner. Make sure that the "3D Buildings" box is checked under the green "Layers" bar.
You can also activate street names, restaurants, hotels, etc. You can add "Placemarks," say for your listings, and e-mail them to your clients. Of course, your clients would need to install Google Earth on their computers.
Better yet, you can add your own proprietary data to Google Earth (if you have the professional edition). You'll find dozens of Placemark collections at Google Earth Hacks (click "File Downloads" in the left-hand column).
Somebody has created 3D images of buildings in Marietta, GA. Another person (or the same?) has created 3D buildings in Dothan, GA. What's the connection between Marietta and Dothan?
Want more? Tour de France stages, bullfighting arenas in Spain, NASCAR tracks? It's all at Google Earth Hacks. Very cool