123D Make
So you just made a cool 3D model, but wouldn’t it be great if you could turn that into a real object you can hold? Well, 123D Make by Autodesk allows exactly that.
How does it do that? It turns a 3D object into cardboard templates. After printing these templates, you can use these to cut cardboards or foams. Glue them together, paint and your virtual 3D object is literally in your hands. The program is a bit different from other 3D graphics software, but it will only take a while to get used to the interface.