This is pritty cool, stare at this page for at least 30+ seconds, (press F11 to make it fullscreen) and then look away at something else, for a cool lsd-trip like effect. http://www.skytopia.com/project/illusion/didgrow.html
Haha, not anything like acid, but a very awesome optical dealy none the less. If you look at the thing and focus very hard, wierd optical stuff with bright colors starts going on. After you look away it gives everything a 'breathing' type effect. The walls and such not become all wavy lookin
