Invention of the Day: Shoes That Generate Power From Your Steps

Engineering students at Rice University have detected a leak in the system of human energy use: the force we waste on the impact of each footstep.

So they've created a pair of shoes that will harvest the energy of the heel strike with little effect on the stride of the wearer. (Researchers at USC developed a similar concept a few years ago that involves piezoelectric crystals, but we've yet to see it in use.)