3D printers can create solid objects from data. In the near future, you may own one. You may buy products printed to your specifications. Or you may know someone who has an artificial body part made by a 3D printer. In this enlightening TED video, Lisa Harouni shows how this technology works and how it might work for us.
http://www.ted.com/talks/lisa_harouni_a_primer_on_3d_printing.html