Adidas have released a free iPhone application that turns your phone into a personal coach.
miCoach uses GPS and real-time voice coaching to pace you through easy to understand workout zones as you run. GPS is used to track your run on Google Maps. Using Google Maps miCoach is able to analyse your run showing your speed, distance and elevation data.
The application measures your distance, pace, calories burned, and elapsed time. It can then provide you with daily planned workouts and coaching feedback delivered to your phone.