The BBC Technology website has an article on a personal fabricator, that is to say a machine that will make just about anything. Rapid prototype companies such as CDRM in High Wycombe and ame-prototypes at Dinnington have been using techniques like stereolithography and micro-modelling. Clark Boyd's article "Hi-tech DIY to solve local problems" reviews some of the uses of the technology in Scandinavia, South Africa and elsewhere.
It is perhaps helpful to consider these machines as a bit like 3-dimensional ink jet colour printers. These build combinations of dots of ink into any character imaginable including photos. These build up shapes from small building blocks of material in very much the same way.