A team from the Computer Science and Artificial Intelligence Lab at MIT has designed a 3D printable robot that (once you've inserted a motor and battery) can walk right off the printer. The process for creating the robot involves having the 3D printer print with both solid and liquids, the latter of which go inside hydraulic pumps, which sounds like it must have been very difficult to do.
And now we are one step closer to having an assembly line that spits out an army of robots that immediately march into formation and await commands from The Emperor. (Or, you know, come to peoples' aid in an emergency. One of those)
• MIT 3D prints a complete walking robot [engadget]