I had some red and white plastic and I thinking what I should make for my first dual extrusion model. This was the obvious choice for me, because the Amiga was my favorite computer. The Amiga was where I first started 3D modeling using Imagine, and then Lightwave.

Video of the original Amiga boing demo.
http://www.youtube.com/watch?v=-ga41edXw3A

Merge the two .stl files. I printed it with 15% infill and 1 extra shell, and a build platform temperature of 110C. Glue or solvent weld the two halves of a sphere together to make a ball, or leave separated for a cool coconut style instrument.