RunKeeper Pro

RunKeeper uses the GPS technology found in the iPhone 3G/3GS to track your fitness activity, giving you comparable results to an expensive GPS watch at a fraction of the cost. Now, you can also enter your activities manually, including your treadmill runs too!

Get it here: http://itunes.apple.com/us/app/runkeeper-pro/id300235330?mt=8&at=1l3vawp&at=1l3vawp