Griffin Technology and Adidas have teamed up to create the new miCoach Sport Armband for the iPhone. Made from ultra-lightweight nylon, the miCoach features a sweat-proof, touch-through screen cover, a low-profile pocket for keys, and a headphone port. While the companies claim the armband was “purpose-built” for use with adidas’ miCoach personal trainer app, it is obviously also useful for users of other athletic tracking and training…