"Look where I've been!" will become your catch phrase once you download a new program called Track Exporter from sports-watch maker Suunto. Made to work with the company's X9 or X9i (above), the free download will take the GPS data from the watch and then plot out your wanderings on Google Earth. You can even do fancy stuff like panning 3D flyovers of the path you took. Avid hikers, runners, mountain bikers, and people with bad memories will love it.
But as Charlie White over at Gizmodo points out, you can do the same thing with Garmin's Forerunner GPS gear with a free download called Foreconv. Just export your history file from the Garmin software and Foreconv will run it over to Google Earth for a frighteningly detailed account of the routes you've traveled.
If you're totally blown away by all this pathfinding but don't own either, you can either find yourself a Garmin Forerunner 301 on Amazon for about $150, whereas Suunto's X9i will set you back at least $375. It is pretty damn hot, though. Thanks to Jenny for the sweet tip!