Bristlebot: Technology Doesn't Have to Be Practical

"Bristlebot: A tiny directional vibrobot" from Evil Mad Scientist Laboratories.

Made of a toothbrush, a battery, and a pager motor, the Bristlebot has no practical value that I can see: but it looks like fun to make and run.

There's a video and a step-by-step guide to making your own Bristlebot.