This stuff instantly fills your car after a heavy collision, acting as a sort of high-tech air bag. The foam is soft enough not to cause harm, but solidifies into a form that's secure enough to keep you from careening dangerously around the cabin. If you've ever read about the collateral damage caused by air bags and seat belts, you know how welcome an advancement this would be.
#28. Safety Foam
As Seen In: Demolition Man (1993)