Alright, so maybe I am a little obsessed with time lapse photos. But still, I think this is pretty cool. It's a cheap but not so cheap ($139.95 on Amazon) waterproof camera that you stick in the ground and leave to gather time lapse photos. Seems there would be a number of uses for something like this, and they do have a sample video of someone using it to make a video out of some people putting up a Habitat for Humanity house.
Via Cool Tools.