3D File Repositories
https://www.3dagogo.com/
http://3dr.adlnet.gov/Public/About.aspx
http://sketchup.google.com/3dwarehouse/?hl=en&ct=lc
http://grabcad.com/
http://www.shapeways.com/
http://3d.si.edu/browser
http://www.thingiverse.com/