this will mess with your head

[dbax]

Ok found this little optical illusion. Well worth a look. If you like you can down load the image and clone the A square into the B square and prove it to yourself.
there is a copyright note that its free to download etc.
http://en.wikipedia.org/wiki/File:Grey_square_optical_illusion.PNG

[kiwi]

very cool illusion

[Analog6]

Amazing!