Products could be produced by technologies such as 3D printing, laser sintering, laser cutting, CNC machines, plasma cutting, etcetra, using a variety of materials. In fact, this sort of idea, rapid prototyping, is mentioned in association with Fab Labs in the Wikipedia article titled Distributed Economy. This rapid prototype could be the final product.
CAD files that are produced by the community could be used as models to produce these products. Economics could be a factor, as is suggested in some sources, but the potential may only be limited by imagination. Many people are thinking about production in this manner.
I found a number of these technologies mentioned on http://www.thingiverse.com/, as well as Wikipedia.