NASA's Goddard Space Center
has been accumulating incredible high resolution images of Earth and then using post-processing software to "stitch" together many small images into detailed high resolution images of the entire planet. Goddard scientists and data specialists have stitched together months of observations in 2001 of the entire planet into a rotating mosaic of every square kilometer. They've even established a Flickr account to display these images, images and research paid for with all of our tax dollars and already being used to track resources, locate lost cities, and research atmospheric changes. You can find the NASA Blue Marble Flickr account here. I've linked to sample image in this post; click it for a larger version, and don't forget to enjoy the animation below.