MAGICAL PEN

A pen that uses plastic for ink allows you to draw in three dimensions. The 3Doodler, invented by Peter Dilworth and Maxwell Bogue, gives people a freer hand in creating sculptures and brings computer-aided design software front and center.

You hold it just like a regular pen, but instead of building a shape layer by layer, as a 3-D printer does, this pen it extrudes the plastic into the air.for detail click on the link
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http://news.discovery.com/tech/gear-and-gadgets/get-a-pen-to-draw-in-3d-for-75.htm