A lot of tips and inspiration for everyone who wants to make cheap (but nice) laser effects.

"I use 2 very common little loudspeakers (diameter is 80mm). On each one, on the radius of the loudspeaker, I dispose a first little piece of wood (a match ;-) (50 mm long perpendicular to loudspeaker axis), glued on the diameter and glued on the centre of loudspeaker (through another little piece of wood 10 mm long on the loudspeaker axis). Then I glued a little mirror on the 1st piece of wood, near the diameter of loudspeaker. When the loudspeaker vibrate, the first piece of wood rotate and the mirror too."

Link: Lasers for amateurs