What's part turntable, part optical-art, part children's toy? A Duchamp rotorelief: a colored, spiral-patterned disk the artist designed to create a three-dimensional visual effect when spun (hence the term "relief").
Duchamp designed them in 1935, and tried unsuccessfully to sell them, not on the art market, but at Concours Lapie, a trade-fair for Inventors. They were first exhibited at jazz club called La Cachette, where they spun at a booth you'd otherwise see the house dj at. Duchamp eventually reproduced them many times over, selling them to a variety of collectors.
Vassar College, ("A highly selective, residential, liberal arts college located in the heart of the Hudson Valley in New York State,"), has a set of rotoreliefs in their permanent collection; they recently posted on their "Off-The-Wall" blog that students in the art department had been playing with the surrealist toys. While spinning them, even if with one eye closed, such solid objects appeared as "a Chinese lantern, a soft-boiled egg, a table lamp, a Bohemian glass, a Japanese fish circling in a bowl, a hot-air balloon, hoops, corollas, a cage, a snail, a white spiral and a total eclipse."
Sounds like about as much fun as one could have at college with clothes on, and within the bounds of the law.