Here is a quick and easy post on how to make tops using recycled items.
What you need:
Old CD or DVD
Plastic bottle cap
Hot glue gun
Cut your paper to fit over the CD or DVD. Let the kids color the paper however they want. While the kids are coloring, hot glue the marble to one side of the DVD/CD. You will want to use more than you think you will need or it will come off. You also want to hot glue the plastic bottle cap to the other side of the CD/DVD in the middle of the disk. When the kids are done coloring, glue the paper onto the CD/DVD on the same side that the bottle cap is on. This can be done with regular glue so the kids can help. Once dry, give them a spin. They will spin for a long time and since there is not a point on the bottom almost anyone can get them spinning. My kids love playing with them and it was an easy to make recycled project.