The Gigapan is a device developed by Carnegie-Mellon University for NASA to take multiple pictures in a very controlled manner and then stitch them together into a single high-resolution image. The grayscale image is about 580MB after flattening.
The above picture was shot several weeks ago at Great Falls on the Potomac River. This single image was stitched together from 22 separate exposures using a Canon 5D Mark II with the 24-105 L lens set at 105mm.
For those of you who are techno-geeks, the above crop shows the detail if the original image was enlarged to 11' wide.