Theoretically - the move is thought on the 4th dvd of the trilogy series - AndThenSome by D&D, and it's named The Two-handed Pirouette - Now, the thing is, it isn't a hard move to do, you just gotta spin a card - it's not that hard. Like the posts before me, I basically say the same thing - bend the cards, turn a card around and just flick your wrist, or, if yo know the pirouette flourish (there is a tutorial in the media section), you just apply the same principle, only you turn a card face up on your bent deck, and rotate it there (it's just like doing it palm down instead of palm up). I hope this helps.
-Spk