The Trackstick II is a small GPS device that logs your position at intervals of 5 seconds to 15 minutes, recording until it's 1MB memory fills up. You can then plug it in to a USB port to see your route on Google Earth. This sounds like fun, until you realize that all you can see is a big, thick, red line between your home and office.
It runs on two AAA batteries, which should power the device for up to a week. [Shiny Shiny]