Videos on Visual Illusions

Bumming around one early morning, I came across these fascinating videos on YouTube of visual illusions reminiscent of Escher's optical illusions... except these illusions are made of cardboard and without use of any magnets or editing (video or computer generated)... just VERY clever use of camera angles. Be sure to watch the end of the videos to see what is REALLY going on.

Much credit goes to the artist who started it all, Kokichi Sugihara. Here is a compilation of some of his work.