Neal Stephenson, in his book The Diamond Age, described engineers as being either forgers or honers:
The distinction was at least as old as the digital computer. Forgers created a new technology and then forged on to the next project, having explored only the outlines of its potential. Honers got less respect because they appeared to sit still technologically, playing around with systems that were no longer start, hacking them for all they were worth, getting them to do things the forgers had never envisioned.
I’m betting the engineers of the Nintendo Wii never envisioned the future hack by this guy:
(It’s worth checking out the other Wii Projects Johnny Lee has on his site.)
Essentially it’s the same principle behind how, when I was in primary school, we made picture whose eyes followed you around the room. We placed a card with the drawn pupils set back about two centimetres behind the cut-out eye-holes of a picture. No matter where you stood in the room the eyes looked as though they were pointed at you.
A variation on this is a concave face, like this guy:
A concave face gives your brain the wrong cues, and you think your looking at a real head. As you move around, the face seems to be turning to look at you. (Download the file and make it for yourself.)