I love Useless Facts. "The plastic things on the end of shoelaces are called aglets".

Not too sure about this one though. "According to Einstein's Special Theory of Relativity, it is possible to go slower than light and faster than light, but it is impossible to go the speed of light. Also, there is a particle called tackyon which is supposed to go faster than light. This means if you fire a tackyon beam, it travels before you fire it". [Sic, as they say. All of it: Sic.]