GoPro HD
I absolutely love this camera. More than any video camera I've ever used, this encourages experimentation. Once you try one, you'll see why.
The GoPro HD is a small video camera in a tough, waterproof box that's designed to be mounted on things. Cars, handlebars, surfboards and so on.
It's basically a helmetcam without the helmet.
There are a number of mounts available, and all of them operate on the same simple principle. Changing the mount is as quick as changing a lens on an SLR.
Here's a bit of sample video (just some birds eating seed in the backyard). More video shortly, along with some detailed specs. In the meantime, there are a few things I'd love to try ...