Bucky balls. Those little metallic balls that are pretty fun to play with for about five minutes and are apparently a hazard to small children.
This posting - somewhat unfortunately - isn't a guide on how to use these little desk trinkets as a means to an explosive end. However, scientists are trying to do exactly that - albeit on a much smaller scale.
Scientists at USC are attempting to use the high amounts of energy stored within the carbon-carbon bonds of the "bucky bombs" as an explosive way to kill cancer cells. It's a rather impressive reaction too - in a controlled reaction, scientists disintegrated a single bucky ball, which in turn raised the surrounding temperature by "thousands of degrees."
Read more on it here