yo
http://www.grand-illusions.com
this is a very cool site with some amazing illusions illustrating how weird our brains are.
My favourite illusion is this one here :
http://www.grand-illusions.com/optic...chequer_board/
To verify they are not fooling you, open photoshop, pick up the colors of the squares A & B, use masks or anything you want to isolate them... and you'll see , it is real and weird !!
enjoy
