I've seen them used also to make live movies (drawings that change in real time according to, for example, a piece of music; an example is here: Mamasonikas en VIVO desde Ciudad de México. Pío Cine a Mano. Urdimbre Audiovisual. Cubetta Records. - YouTube) www.youtube.com/watch?v=H1lL...)

I rescued one about to be thrown away as trash. Still use it to teach physics/waves using moire patterns.