Funny this should come up i am actually in the process of building one, i'm just working on the sliprings at the moment (tho rather stupidly decided that i wanted to be able to address each LED individually instead of as one hey it's only 6 more spinning contacts) I'll start a construction thread in the "Other light sources" board if people are interested I'll also plan to keep the motors synchronised and control the Illumination of the LED's with a Pic/computer so hopefully i should be able to get some interesting results tho i warn you it may take a few months to get this done as i have a lot on at the moment and only pennies and a junk box for materials...
The mind is like a parachute, It doesn't work if it's not open...