There are a variety of free and paid apps out there that can use your smart phone’s GPS signal to track and map your outdoor activities. My favorite one was just upgraded to My Tracks v2. MyTracks can record your GPS tracks and also allows you to share and export them, for viewing in other programs. You can export to Facebook, Google+, Twitter, and to GPX format if you wish to view the track in Google Earth or upload it to make a custom MyTopo map.
(Via Android App Store) My Tracks records your path, speed, distance, and elevation while you walk, run, bike, or do anything else outdoors. While recording, you can view your data live, annotate your path, and hear periodic voice announcements of your progress.
I have found it to be very accurate and it doesn’t consume the battery quickly as fast as other programs I have used. The best part of all, it’s free! Just remember, GPS is NEVER a substitute for a map and compass or common sense.