Believe it or not, these work great. They are acoustic chambers that focus the sound from an iPhone such that you can turn your iPhone into a nice “amplified” sound system without an amplifier.
The company that designs and sells the acoustic chambers is Simply Amplified. They outsource the actual 3D printing to a 3D print service firm: http://www.growit3d.com/
These are shown being demo’d at the 2013 CES.