I saw this on tumblr and it was too awesome not to share (wow I say that pretty often huh?). According to the post, this ad is "the world’s first eye tracking poster, developed for Amnesty International’s campaign against domestic violence." When you're looking at the poster everything seems peachy, but when you look away you see the truth.
The genius of this poster is breathtaking. You can read more about eye-tracking and how it works here. I can't wait to see how this technology is used in other applications.