3D printing allows you to print any 3-dimensional object (latest update includes printing of a car and gun)

 Additive manufacturing or 3D printing is a process of making three dimensional solid objects from a digital model. 3D printing is achieved using additive processes, where an object is created by laying down successive layers of material. 3D printing is considered distinct from traditional machining techniques (subtractive processes) which mostly rely on the removal of material by drilling, cutting etc.
3D printing is usually performed by a materials printer using digital technology. Since the start of the twenty-first century there has been a large growth in the sales of these machines, and their price dropped substantially.



The technology is used in the fields of jewellery, footwear, industrial design, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical industries, education, geographic information systems, civil engineering, and many others.

Recently a group called Defense Distributed recently published instructions for creating a plastic firearm using a 3D printer. One guy even fired a real bullet with one.
An Israeli company Stratasys, already a major player in the field  and its subsidiary, RedEye On Demand, will be part of a project aimed at putting the first 3D printed car on the roads within two years, in partnership with KOR EcoLogic.

This means you can print any physical object as long as you have the digital blue print, the economic potential is stunning. Across a range of industries, research and development costs are declining and product development cycles are accelerating as more inventors experiment with cheap 3D-printed prototypes. Consider the Urbee 2, a car being produced by Kor Ecologic using a 3D printer. When completed, it will weigh 1,200 pounds. Made with about 40 pieces of thermoplastic, it will be resilient, aerodynamic, and mind-bogglingly efficient. It will need almost no labor and little time to assemble.

With this technology you can print anything, the problem of such technology is violation of copyright laws because people could start printing counterfeit goods from the comfort of their homes.