The Forerunner 405CX is the evolution of GPS-enabled training. This sleek sport watch tracks your distance, pace and heart rate, then wirelessly sends the data to your PC for later analysis. The 405CX features heart rate-based calorie computation and comes with a second wrist band option suitable for smaller wrists.
This is an amazing watch for training, it tracks everything and allows you to compete against your own virtual partner. You can save the data as a .pgx file and overlay it onto Google Earth to map where you have run.