MakerBot Thingiverse [1] is a repository of designs for 3D printable things for use with RepRap 3D printers [2], humanity’s first general-purpose self-replicating manufacturing machine.
Referenced from: J.M. Pearce, Commentary: Open-source hardware for research and education. Physics Today, November 2013, page 8 [3].
[1] Thingiverse http://www.thingiverse.com/
[2] RepRap http://reprap.org/wiki/RepRap
[3] http://dx.doi.org/10.1063/PT.3.2160