Google Earth
Wow. This has to be one of the coolest things I've seen in a long time. It is a globe. But it is made of satalite images! I can see my truck parked infront of my house! It will render 3d terrain, 3d buildings for some cities, borders, roads, dining, lodging, whole POI database, works with GPS, it will grab demographic data and lay over the map, weather, crime rates... This program is amazing! I've played with it way too much today and haven't even begain to get to all the features. If you have a few hours go check it out.