The Nike + iPod Sport Kit comes in a display box about the size of a double-CD jewel case. It prominently displays the miniatures inside: a postage-stamp sized receiver that plugs into your iPod nano’s dock-connector port, and a track-shaped sensor/transmitter about the size of a large piece of Bazooka gum. The transmitter fits snugly inside a matching compartment hidden under insole of the left shoe of a pair of Nike+ shoes, which range in price from $100 to $130. (Apple says the transmitter’s battery, which isn’t replaceable, is designed to last 1,000 hours.)