So far, Amazon's contribution to the great wide world of 3D printing, where you are limited only by your imagination and stash of printing filament, is bobbleheads. Amazon has opened a 3D-printing marketplace, offering customers the ability to buy customized products and trinkets like earrings or figurines. To enable customization, Amazon has built a new interface on top of its normal product pages that allows buyers to tweak the look of different 3D products. There are plenty of 3D print-to-order businesses already in existence, including Sculpteo, Shapeways, and iMakr.