In this video Darius Groza takes advantage of tourists taking forced-perspective photos of themselves propping up the Leaning Tower of Pisa by running up and giving them high fives when they're not looking: Brilliant.
The Big Ben is leaning! Not as much as the Tower of Pisa, but you can see it with the naked eye. Right now, it's at an inclination of 1.64 feet at its highest point. And it's getting worse.
So simple, really. The Italians just wanted to emphasize it a little more. I do that all the time. [Bits and Pieces]
Normally they're contained in a box, so the fact that this 3D printer isn't confined means it's theoretically capable of building much larger objects that most. In fact, the owner wants to build a cathedral with it.