NASA released World Wind under an open source license recently.
World Wind allows any user to zoom from satellite altitude into any place on Earth, leveraging high resolution LandSat imagery and Shuttle Radar Topography Mission (SRTM) elevation data to experience Earth terrain (or any planet with the data) in visually rich 3D, just as if they were really there. Virtually visit anyplace in the world. Look across the Andes, into the Grand Canyon, over the Alps or along the African Sahara.
it is very easy to be immensely impressed by the pretty pictures, but the potential of the platform for documentary purposes (or even entertainment) is hard to overstate. yet another opportunity for me to link to spacenamespace