Nike+ Training on the Behance Network / "Smart sensors imbedded in the sole of Nike shoes communicate via Bluetooth to an iPhone app to track your sport activity."
Plastic, aluminium, black
HipKey - eep track of your phone, your belongings, or even your kids with the HipKey ($90). This aluminum and plastic disc pairs with your iPhone or iPad via Bluetooth Smart, alerting you at your chosen distance when the two drift too far apart.
I need this badly. Jot Touch 4 – iPad And Tablet Stylus by Adonit