Only tangentially chess related but good fun nevertheless ...
http://www.newscientist.com/blogs/nstv/2011/03/friday-illusion-mind-bending-checkerboard.html
Fantastico
Only tangentially chess related but good fun nevertheless ...
http://www.newscientist.com/blogs/nstv/2011/03/friday-illusion-mind-bending-checkerboard.html