If you're serious about your running and would like to track and map your extended trail runs, the Timex Ironman Run Trainer S and D is the ticket. This multi-function training watch is also a GPS. You can track your distance in real time and map it on the computer when you get home. Of course, Timex includes all of the features that have made their Ironman watches so popular like multiple alarms, countdown timer and a hands free chronograph. You can view four lines of data at any time and store up to 15 workouts. And, you've heard right, the watch reasonably sized so you do not feel like you are sporting a wrist-top computer. The Timex Ironman Run Trainer is a must have training gadget for any dedicated runner and data fiend.