Off the top of my head:
The Vernon Five Card Mental Force (page 30 of the Dover edition of The Encyclopedia of Card Tricks)
Of simply control a card to fourth position with a shuffle and then false cut saying that you believe you are within five cards of the selection. Then show the top five cards asking them to confirm that you are "close".
Finally, ask them to hold the packet of "five" cards and concentrate on the selection. Top palm the selection as you table the remainder of the pack and proceed to have the card vanish from their hand a reappear anywhere you like.
I'd recommend you ask then to think of a card and remove it from the pack before the control.
Still having too much fun with my new twist on "The Magic Cards" to have spent much time on the countback....
PS - Richard and Geno...
Thanks again for this great set of DVDs