Autodesk's 123D Make is a fantastic piece of software that, when paired with a laser cutter, enables you to quickly produce real-life 3D models. The user takes a virtual 3D model and imports it, then the software slices it up into panels that you can either laser cut or cut by hand. After that, assembly is easy peasy. Check it out:
The software, which is currently Mac only, is free from now until late February 2012. Download it here.