The paradox that is created when someone tells you that he or she is a liar. If he IS a liar and tells you that he is a liar, then he is telling the truth and can't be a liar. If he is NOT a liar, but tells you that he is a liar, then he is telling you a lie, so he must be a liar.
"Hey George! Don't believe a word I say!"
"Man, that's fucked up big time. If I believe what you are saying now, it means I must not believe you, and if I don't believe you, it means I have to believe you! It's the Liar's Paradox!"
When a video taken by an i-Phone in vertical portrait mode is stretched horizontally to fit the aspect ratio making people look like penguins.
Hey dude! You i-Penguined a video again in your Facebook timeline!