Eyebot 2000
Please note that this video is pure research — all theoretical; nothing practical. No small portion of the credit goes to the SighTech EyeBot‘s wayward edge-finding algorithm, which apparently found itself through backpacking around Europe. However, ffmpeg also deserves an honorable mention, as having to repeatedly recompile it gave us plenty of time to think.
You can read a full writeup on the EyeBot here, or buy it on eBay.