Easy GPS Tracker
Easy GPS Tracker is, like you may have guessed from the name, an easy GPS Tracker for the iPhone. Just activate the tracker with the big “On” button. When finished tracking, you can view your saved tracks right in the app or send an email with your track attached as KML.
I recommend using Google Earth for viewing those files. It has some pretty neat built-in features like an elevation/speed view. You can access it with the menu. Make sure you have selected your KML.