Reconstructing reality from photos
This is one of the most interesting applications I saw over the past weekend:
Click to viewIt takes everyone's vacation photos online, and then uses image processing algorithms to match features and figure out the shape of what had been photographed and the position it had been photographed from. Then, the pictures are stitched together in 3D so that you can navigate from picture to picture. It's a beautiful concept, and it shows how online photo sharing can be taken to a totally new level.
About 4 years ago, I took about 500 photos of every corner of my apartment, figuring that the technology would exist one day to use all those photos to reconstruct my apartment in 3D. I guess that day is closer than I thought.