Using Michael Faraday's 19th century discovery that a cage of conductive material will stop electromagnetic fields from crossing the threshold, Nissan created its concept "Signal Shield." Masquerading as a driver's armrest for a Nissan Juke, the cage surrounds the internal storage compartment. Slip your phone in there and cellular, Bluetooth and WiFi signals won't be able to reach it, disconnecting it completely from the outside world and making the vehicle a "phone-free space" -- though Nissan says you can still get at your tunes by feeding a USB or aux cable in there.

Smartphone distraction is a very serious issue, of course, but there's a reason Nissan's Signal Shield is unlikely to progress any further than the current concept stage. Because if people won't go to the trouble of actually using their phone's 'do no disturb' mode, then they're just as unlikely to cut themselves off by way of armrest Faraday cage.