The technology has been around for a while, but researchers recently began using it to create biological structures like organs. The idea is to use the patients cells to design organs that the body would accept creating no need for donor organs. Another possibility is that we will use it to grow meat. Imagine being able to print out a steak for dinner, that would be amazing!
Right now you can buy a 3D printer which doubles as a 3D scanner, the Fab@home, which allows you to email physical objects to other Fab owners and it will be printed out of your choice of silicone, cement, cake frosting, and even cheese.