Instructables is usually a good site to find interesting builds, ideas and hacks but an instruction set I found recently stood out of the crowd. The Instructable takes you through multiple ways to make a below the knee leg. The Author, Pat Maroney, works for a company that makes them commercially and they customise each leg for its user and hence he is well qualified to explain this.
In the normal Instructable way it breaks down the process in to multiple steps. These are making a diagnostic socket and fitting it to the leg, single stage lamination and construction of a definitive socket, two stage lamination of the definitive socket and finishing off. He goes into great detail and explains the different options and customisations available at each stage.
Finally Pat talks about 3D printers, K-Levels and some of the things that will be possible in the near future. If you are the least bit interested in prosthetics or making its a very interesting and in depth look at something that we do not usually get a chance to view the details of. The post is quite picture heavy and explains the process in a simple enough way for even those who would not think themselves very crafty to understand.