Van de Graaff generator
A Van de Graaff Generator is an electrostatic machine for generating high voltages, it consists of a metal sphere mounted atop an insulating column. A continuous belt of rubber runs from a pulley at the base of the column to a pulley connected to the sphere. There is a metal comb with sharply pointed teeth mounted parallel to the moving belt. As the belt carries its charge up to a comb connected to the sphere. This is the device popularized by the idea of hair standing of edge due to electrocution. My modest version is a measly 20cm high powered by 2 AA batteries, its belt is a simple rubber band. As they say: simple is elegant.