While this doesn't have any practical application in the world of actual industrial design, where the name of the game is precision, there's no denying this thing is neat: The 3Doodler is a pen that lets you "sketch" in three dimensions, something like a 3D-printer stripped of everything except the printing head.
Invented by Boston-based toy & robotics company WobbleWorks in the Artisans Asylum hackerspace, the 3Doodler uses ABS, which cools quickly enough that strands are able to support themselves (up to a point). Check it out:
(By the way if you're thinking of getting one of these for your kid, be aware that the business end gets at least as nasty-hot as a hot glue gun: The metal tip can get up to 270 degrees Celsius.)
At press time the project had been successfully funded on Kickstarter several times over, at $138,000 over a $30,000 target with more than a month left to pledge.