The Verge just posted a video giving a peek at Microsoft's model shop, where hardware prototypes for keyboards and other devices are designed and printed in 3D.
"Karsten Aagaard, user experience designer, says that the team tries to print 3D prototypes in "real-time" so that designers can work rapidly. If a prototype design is submitted at 5PM, the team endeavors to have them printed by the time the designers return the following morning," the Verge said.
Check out the video:
Here is the longer segment of the Microsoft Research in Redmond, a personal tour - On The Verge: