Earth View, a cool astronomy service

We discuss both mashups and location-based applications. This image shows the earth from a 1,000 kilometers above our campus. It will be dark or light depending upon the time of day.

It was generated using Earth Viewer, which can display various views of the Earth from various vantage points, for example, from the Sun or Moon. I used Geocoder to get our campus coordinates.

With the coming of low cost, location-aware cell phones and other portable devices, people predict that we will see a lot of location-based advertising. Can you think of other location-based applications? Can you think of applications you could build on top of Earth Viewer?