another one is usaphotomaps. not sure of the url and too lazy to verify. That one runs off terraserver pictures but it's an application that has some really neat added features. You can pull in your waypoints and tracks from your gps. you can also hook up your gps and (if using a laptop) it will show you right on the satellite picture where you are. Works good for scouting new land (assuming you're driving around in a vehicle, not so good walking around ).