Who remembers the Nike+ iPod Pedometer? Went in your shoe under the insole and connected to your iPod via a separate 30-pin dongle. : r/RunningShoeGeeks
Nike+ sensor logo on running shoe's sole Stock Photo - Alamy
Put an IPod Nike+ Sensor in Any Running Shoe in One Minute for 5 Cents : 4 Steps (with Pictures) - Instructables