We've all heard of these replicators that use cornstarch or plastic or whatever to create solids from a CAD image. However, Dr. Adrian Bowyer at the University of Bath—that's a city, not a discipline—in the UK, has created an open source replicator, the RepRap that uses glue or heat to bond layers of a solid. It can also print circuits using blobs of solder. Bowyer has GPLed the source and design for the replicator and hopes to make it available to the world for quick and easy creation of household objects and other devices.
Thus far, they've been able to create prototype robots and quite a few pieces for the future, final version of the RepRap.