Some American and Canadian skiers competing in the Olympics have a secret weapon: a flexible form of "body armor" that's molded to the shape of their bodies and hardens on impact. The material, known as d3o, and developed by scientists working with skiwear maker Spyder, contains a proprietary polymer that has "strain rate flexibility." While normally flexible, sudden impact hardens the molecules of the material, making it as protective as the traditional arm and leg guards worn in slalom runs. The developers envision expanding d30's uses to other purposes, including protection for military and police personnel. Unfortunately, they don't seem to have any plans for a material that can protect Bode Miller from himself.