NASA recently published a high-resolution topographic map of the Earth, created from satellite photographs.  It was remarkable not only for its detail, but for the fact that it was 2.9GB in size (86400x43200 pixels), and that it was distributed using Bittorrent.  Pretty cool.  For those of you who don't feel like downloading the file, you can still view it in comfort right here in your browser, just click this image:

(After clicking, hit F11 to maximize your browser's window.)

This same problem confronts Pathologists who want to view digitized microscope slides.  The images are so large they cannot practically be transferred over wide-area networks, not even with Bittorrent.  But using incremental client/server viewers like Aperio's, they can view any part of the image at any resolution.  Pretty cool :)