Bozardeux wrote this Instructable detailing his OpenReflex, the open source 3D Printed Camera:
The OpenReflex is an Open-Source analog camera with a mirror viewfinder and an awesome finger activated mechanic shutter (running ~ 1/60°s). What’s more, it is compatible with any photographic lens. All the pieces are easily printable on any recent RepRap-like ABS 3D-printer without using support material! Everything should print in less than 15h and anyone should be able to assemble it within 1h. All parts are separate ( Film receiver, Shutter and Viewfinder ) to simplify builds and modifications. The source files are available under the CreativeCommon By-Sa license, feel free to modify them if you want a new feature, and don’t forget to share your improvements on the web. ;)