iMapMyHike uses the built-in GPS technology from your iPhone 3G to help you achieve your fitness goals.

Features:

– Real-time tracking with distance, time, pace, and speed display
– Support for mile or km output
– Synchronization with your training log and routes on MapMyHike.com
– Viewing of your training history (with maps) from your iPhone
– Twitter integration

http://appshopper.com/navigation/imapmyhike