The basic design is simple, my mom says she used to do it with buttons. You put a string between two or more lights, wind very tightly, and if you pull hard enough the lights will spin very quickly.
Here's a 3d orbit
I've made large orbits that have to be used by two people, each person pulling the string at the exact same time. Trying to do tricks was impossible; in order to make the "stars", you have to twirl the orbit in the opposite direction it is spinning, and trying to coordinate was too hard. This diagram below is my most ambitious human powered machine, but you would be unable to do tricks like the stars or spirals. I had a harvard architect recommend a good program for blueprints.
From the front From the side All it requires is the Orbit (minimum two lights but I'm looking at more like 1000-2000), two poles with holes through the top, strong line, handles at the end of the strong line, and bases for people to stand on. The disadvantages are that it's human powered, and I"m not sure how many volunteers I'd get (in reality it would take more than one person per side), and tricks would be impossible.
Here is a smaller version, about 7 feet high, with a tire for the orbit. LEDs would be attatched to the tire tread, I estimate 6 LEDS accross. This is a more econimical design, and pretty simple in terms of setup. A tire might be too heavy, a bicycle wheel is what I used last time. Sideview of the tire, white spots are where the holes go, the red lines are just leds. There would actually be 8 holes, four on either treadlug, each one in line with the corresponding hole on the opposite treadlug.
Well, I can't add it, so I'll add it in another post, along with a diagram of the bicycle wheel orbit, which was made without supports.