iTrackYou turns your iPhone into a personal GPS tracking device that lets you record your journey as you bike, run, wakeboard, paraglide or trainsurf! Then (assuming you survive) you can replay your journey later on your phone, or even import it into Google Earth and replay it on your PC!
iTrackYou records your position, speed and altitude as you are moving and then lets you display this on a map or as graphs of your speed and altitude.
You can store a history of multiple journeys on your iPhone, and can even export journeys to your PC or Mac so you can view them on Google Earth. Once in Google Earth, your journeys can be replayed as an animated track on any of the map, satellite or hybrid views.
Altitude and speed graphs can be displayed in either imperial or metric units, and you can adjust how accurately iTrackYou records your journey by increasing or decreasing how often your current position is recorded.
Disclaimer: Continued use of GPS running in the background can dramatically decrease battery life.