Forbes.com: Sensors gone wild Early this year a pilotless aircraft sprinkled three dozen cheap wireless magnetic sensors, each about the size of a credit card, along a road at the Marine Corps Air Ground Combat Center in Twenty Nine Palms, California. Once they hit the ground, these sensors automatically formed a wireless network and began to scan the environment for magnetic signals. When a vehicle rolled by, they could tell from its magnetic signature what kind it was, its speed and direction. The readings were sent wirelessly through the aircraft to headquarters.