Awesome mad scientist Ben Krasnow built a hybrid rocket out of a transparent acrylic rod, thereby allowing us, the viewer, to see how it all works. A bit of explanation on the actual mechanics:
I lit the engine by inserting a burning cotton swab (with wooden stick) while a small amount of oxygen was flowing. The acrylic catches fire very easily in a pure oxygen environment. The engine can be throttled and shut off completely, which is a major benefit to hybrid engine designs. Solid-fuel rockets cannot be throttled or shut off, which makes them difficult to control.
Watch the rocket get spent - and learn a little something, too - AFTER THE JUMP.