There are plenty of wrist-worn fitness trackers available for data-obsessed athletes out there, but few offer the feature-set boasted by the Adidas MiCoach Smart Run Watch ($400). While it does everything you would expect from a device that tracks your physical activity — a pedometer to measure your movement, and access to historical data to chart your progress — it also packs in some other useful features. Built-in GPS keeps track of your speed, distance, and your favorite routes. An on-board coaching system will help you train more effectively, whether you're getting ready for a 5k or your first marathon. Perhaps best of all, it features an MP3 player with wireless Bluetooth audio, so you can say goodbye to extra gadgets and obnoxious headphone cables.