Today was Market Day at my youngest son's school (5th grade). The students had to sell a product they had made themselves. Pablo made and sold tops assembled with recycled CDs or DVDs and a marble, with the label covered with acrylic paint. He ran out of tops to sell, so I guess it was an attractive product for the kids.
The inspiration was, of course, the old tops from Toycrafter. Using a marble as the tip and stem, instead of a penny, facilitated the construction, although it left little room to grab it. The idea of making tops out of old CDs is an old idea, but generally the suggestion is to use a pencil.