A big point I try to get across to my students, in my classes in the Learning Technologies Center at the Museum, is that when they learn how to turn bits of information on and off, they can take that skill and apply it to wide range of cool stuff in the material world.
Geyserbot came about as I was trying to come up with an interesting demonstration of bit sequencing within a byte (8 bits). I had scored the pumps at one of 3M's monthly auctions several years before, and rescued them from my "eternal storage heap." Now, after students successfully demonstrate their programming skills on a "Lyte Byte" (8-LED's), they take their BASIC programs over to Geyserbot and play them there.
See a brief demo: