I built a lamp for my girlfriend. It’s quite simple: I took a rotating part of a lamp I broke some time ago (some stupid aquarium simulation), a spare 3 color Cree LED and chicken wire. A little cheesy but quite nice. If you lie on the ground an watch it for some time, the spiral seems to stop and the room rotates instead.
the knob lets you choose the color or the speed the color changes
the turning mechanism
inside: a 12V power supply and a constant current supply for the led, an atmega 328 (arduino)
Of course, the Atmega32-8 is completely oversized for such a project, but it was at hand and programmable via the Arduino. I’m sure the extra constant current supply is also obsolete, but I didn’t get to try otherwise. Comments how to optimize the setup are always appreciated.