Open collaborative design/Virtual designs into physical objects

To be useful to anyone these designs need to turned into physical objects which unfortunately isn't quite as straightforward as compiling software or downloading it over the internet.

Ways to realise collaborative designs range from the age-old get your hands dirty and craft it yourself to sending it (or at least parts of it) as an electronic file to rapid prototyping or CNC machines that can accurately create parts in 3D in a variety of materials.