Most video cameras with a motorized pan and tilt mode move pretty slowly, and can't respond nearly as quickly as a human eye. This one, created by a group of researchers at the Munich Technical Institute in Germany, not only keeps up with a human's eye, but can actually outpace it.
In the video, it starts out pretty slowly, but then at around 30 seconds it starts to go nuts, making motions that almost look like they're impossible.
The implications of this technology could be pretty dramatic. By adding eye tracking technology, you could create a small wearable camera that creates a record of everything a person is looking at. Perhaps an implanted version of this camera could be used as an artificial eye for the blind, although that would also involve finding a way to deliver a video signal directly to the brain.