Nike+ iPod Sport Kit
Hear how you run.
The Sensor and Receiver enable your Nike+ shoe to talk to your iPod with every step.
Instant audio feedback:
iPod tells you your time, distance, pace, and calories burned while you run.
Go further with nikeplus.com :
Sync your iPod to see your runs, set goals challenge others, and more.
Compatible with iPhone 3GS or later, iPod touch (2nd, 3rd, and 4th generation), and all iPod nano models.