This activity combines art, science, and play. I'm not overselling it when I say, it's downright mesmerizing. Both my boys played with these tirelessly, and it was only until it was bedtime when they were forced to stop (truthfully, I had to confiscate them). Even my husband said he wanted one for his office. I can just picture him spinning and spinning while on long teleconferences. Any how, enough already. Here's what we did and how. All you need is: Old CDs Marbles Plastic bottle caps Hot glue Paper (we used printable CD labels) Markers On printable CD label stickers, we divided most of the labels into quadrants or eighths by folding. Then we colored them using markers, choosing colors that when combined make another color: blue and yellow = green black and white = grey red and yellow = orange We decorated two additional ones however we felt - one with dots in a circle, and the other with numerals. (If you don't have CD labels, cut paper in a circular shape the same size as the CD and cut a hole in the center, tracing the CD to get the right size. Then use glue to adhere it. Or use permanent markers and draw directly on the underside of the CD!) Once the labels were stuck on, we applied hot glue liberally around the hole on the bottom of the CD and stuck a marble (the small ones work perfectly) in. Within a minute, the glue had hardened and the marble was secure. Now we applied a ring of glue to the top of the CD around the center hole (on top of our colored label) and added a plastic cap. All that was left to do was grip the cap and get our tops spinning. It was SO much fun to see how the colors blended together. Our dotted top looked like it had a circular solid grey line on it, which my son was surprised by. We studied the tops a long time. Sometimes the color we expected only appeared when the top's spin began to slow, other times it was immediately apparent. This was a perfect indoor activity for a hot summer day. Our inspiration came from Mini Matisse and the wonderful book Science Wizardry for Kids.