Amazing and simple card trick made possible by math, not sleight of hand
Read an explanation in the comments at Boing Boing.
(via TYWKIWDBI)
Read more: http://twentytwowords.com/amazing-and-simple-card-trick-made-possible-by-math-not-sleight-of-hand/
I just got a deck of cards to try this, and when I picked a pile and turned it over, I got the 2 of diamonds!