Aluminum Foam

Austrian company Metcomb Nanostructures has succeeded in making an aluminum foam with uniform-sized cells. The foam can be made in various absorptions (cells sized from 2mm to 12mm) and is "strong, light, energy absorbing, vibration and noise absorbing, nontoxic, and 100 percent recyclable." You can add to that the fact that aluminum foam is much thinner than its current polymer counterpart. The company believes the first commercial applications will be to protect vehicles and buildings against terrorist blasts. In the future we will probably have this standard in our car doors.
via TechnologyReview