I've kicked this one around for a long time, it's pretty cool. I thought it might be of some interest to whomever. Here is the description:
Deck is shuffled. Spectator selects a card (Jack of clubs for example) and replaces it. Deck is shuffled again. Deck is placed on table and spectator is asked to remove approx 1/3 off the top. He is then asked to deal his pack into 3 piles, face down, on the table.
The performer shuffles his part of the deck to reveal the spectator's card.
He produces what is supposed to be his card, but instead of spectator's card, it is (for example) the 3 of Hearts.
The performer turns the 3 of Hearts face down and touches the top card of each packet on the table with it. When each card is turned over, they are all 3's. The performer now turns his 3 of Hearts face up to display the remaining 3. Instead of a 3, it is the Jack of Clubs... the spectator's card. The performer then slides the face up Jack of Clubs under each of the 3 piles, and flips each pile over to reveal that the bottom card of each pile is a Jack.
If anyone is interested in the workings of this,
I'll be glad to post it. I don't know how many people (if any) would like this card trick, but I figure... what the heck.