Since this comes up occasionally - a few uses I have come across recently -
Clock faces - the CDs were painted - embellishments added - then the
clockworks -
Book covers -
Wheels for car models - Kelvin Electronics sells adapters to fit inside the
opening so that the axle (1/4" dowel rod) fits - if it fits for an axle -
can also be used for sculptures.... (kelvin.com....CD Disc to Wheel
Converter / Reducer, Price: $2.95 Cleverly converts your outdated or
unwanted CDs into a fun wheel. Designed to fit 1/4" dowel rod. 20/pkg. )