I have a Garmin GPS Forerunner unit I use for running. I occasionally will strap it to the handlebar to check speed(I am 5 mph on highside). Anyway, I connect it to my computer and can see the "route" that I road, after the fact. I love technology and stuff like this.
Someday I'll spend the $ to get a nice one for my bike...but not for directions...just because it's a gadget and I love seeing where I've been.