Ever wonder how long you have been running or pedaling a bike? Would it be nice to know how fast you are traveling, or share your location with other people? All of this and more is now possible as Google has announced My Tracks, an application for phones, running the Android OS, which is currently just the G1. Using the phone's GPS, My Tracks records your movements outdoors on a map and shows real time information like elevation. All of this information can be shared with your friends, loved ones and even the curious through the use of Google Maps. Archive the history of your training with Google Docs. With this application you can get statistics in real time like average speed, distance, total time of training and elevation. Describe places you have been and mark them for others to find. While doing any outdoor activity, you can record and visualize GPS tracks. Find this in the Android Market by searching for "My Tracks". After you install the app, hit "Start Recording" from the memo.
source: The Official Google Blog