I have loads of CDs that we never listen to anymore (adults). I'm considering sending the lot to the charity shop, because I could really do with the space. I've seen lots of cute ideas on pinterest for things to do with old CDs and have offered some as craft activities in the past, but they have never really been a huge hit.

Off the top of my head we've tried:
Using them as a pond/frozen lake in small world trays
decorating with glass pens in mandala styles
general decorating with acrylic paint or collage materials
using them to make snails and other garden animals
making mobiles and watching the reflections dance around
sorting shiny and dull objects
added one to the shape box

I guess they are really good for posting activities too.

Have any of you thought of some irresistible ideas for old CDs?