accelerometers

Keeping count of repetitions in any sporting endeavor is surprisingly challenging, be it push-ups, wind sprints, or golf shots. Trying to keep count with water between your ears leaves many swimmers pruning in the wet stuff longer than necessary. The brand new Pool-Mate watch is the first automatic lap counter, promising to help the swimming world count to ten.

How much air is big air? Just check your iPhone. The latest application for the iPhone is Hangtimer, which allows skiers to quantify just how big they went. Download the application for an absurdly cheap $10, and the iPhone's -- or iPod Touch's -- internal tri-axial accelerometer detects when your feet leave and touch the ground. After each jump, the iPhone displays your flight time, while a plot provides a running tally of your jumps and speed throughout the day.