Oh, yeah. They're lying...

Ever watch "Lie to Me"? The show is basically built on screen shots like this:

It's stunning to me how our unconscious, nonverbal communication is so consistent. Certain emotions evoke certain expressions--almost universally. I wish they taught college courses on it. I know I'd sign up.
Body language. I love it. Pictures like this make me want to pay more attention to it... starting tomorrow :D
When it comes to body language, what have you noticed is a universal "tell" into what a person is really thinking/feeling?