body language

Does a trick where a magician merely asks a spectator to think of a card and then the magician reveals the card exist? Does anyone sell a trick like this? Is it in any books? Thanks a lot!

Found this example and have seen others like it. Seems to be real body language analysis. Any thoughts on what are the strongest cues to go by? Eye flickering or stiffness of face maybe? v=3NAbxaE80L0

I have been looking into body language a lot and facial cues in particular. When it comes to facial cues and eye reading a lot of what I run into is classic NLP stuff, which according to most studies I've seen is more or less miscredited. This actually is interesting in itself in that on the one...