Two years ago we featured an incredible video of the Antikythera Mechanism—an ancient Greek computing device found in a shipwreck in 1901—made entirely out of Legos. The Antikythera Mechanism calculated the positions of astronomical bodies with extraordinary precision.
This machine, by contrast, moves little plastic balls around for no particular reason. But, my goodness:
The machine took 600 hours to make and moves the balls around a 31-meter-long pathway. It's loosely associated with the Great Ball Contraption project, a community dedicated to "Lego Technic or Mindsorms creations that all have a single task in mind—moving balls around! That's it. However you want to do this is entirely up to you." This contribution, by YouTube user Akiyuki, was two years in the making, according to his Web site.