Turning a CD spindle case into a plant propagator or other botanical project is an incredibly easy project.
CD spindle cases can make convenient little greenhouses for starting seeds for the garden, growing humidity-loving plants indoors, or making school projects. You can find them in various sizes and probably have a few lying around just waiting to be upcycled.
Basically, all you need to do with your empty CD spindle case is cut off the central column, cover up the hole in the base, drill some holes in the top cover, and add your pot and seeds. Voila! Check out the video at Atomic Shrimp to see the project being made.
CD Spindle Case Propagator [Atomic Shrimp]