Part of a design for a spectrometer for analyzing coffee -- read more here: http://publiclab.org/notes/warren/08-08-2013/design-for-coffee-spectrometer
Also find it here: http://www.thingiverse.com/thing:133556
The design is not complete; it will require a diffraction grating, spray-painting the interior black, a collimating mask, an LED light source, and of course, a smartphone running http://spectralworkbench.org. Follow along at http://PublicLab.org.
However, this model, created in Sketchup and exported as an .obj, printed really nicely on Shapeways. (https://www.shapeways.com/model/1262738/coffee-spectrometer-housing.html)
Design released under the CERN Open Hardware License 1.1 (http://publiclab.org/licenses)