North Paw

"A North Paw is an anklet that tells the wearer which way is North. The anklet holds eight cellphone vibrator motors around your ankle. A control unit senses magnetic north and turns on and off the motors. At any given time only one motor is on and this motor is the closest to North. The skin senses the vibration, and the wearer’s brain learns to associate the vibration with direction, giving the wearer an intuitive sense of which way is North. Most people “get it” mere seconds after putting it on, and can then reliably point north when asked."