Do you ever go for a bike ride, jog or walk, and have no idea how far you went? I used to get in the car and drive the route, but sometimes I'm on paths where I can't drive.
I found a fantastic site called MapMyRun.com which allows you to plot your course then tells you how far you went. It works as an overlay on google maps, so even my tucked-away suburban roads are on it! What fun!
Mel