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.
I love this watch. I have been using for tracking and mapping my training for a half marathon. The included program allows you to overlay your tracks on Google Earth.