Card Trick #4: Identifying a Random Card (Multiple Deals)

Deal a row of three cards.
Continue dealing overlapping three cards per row until you have three columns of seven cards.
Ask your friend to select and memorize a card, and tell you which column it's in, but not tell you what it is.
Pick up the three columns of cards, making sure the column with the chosen card is in the middle of the stack.
Deal again in the same way - seven columns of three cards. Ask your friend to identify the column with the chosen card. Gather up the cards witht the chosen column in the middle of the stack.
Do this again twice.
On your fourth deal, the chosen card will be the middle card of the middle column.
At this point, you can pretty much reveal the chosen card any way you like. Shuffle the cards, cut them, fan them out and pick it out as if by magic.
Even better, use the Magician's Choice. This force basically uses selective discard and retention of cards to give an illusion that your friend is the one choosing the cards, but in reality you're forcing them to choose one.
For example, lay out the chosen (middle) column into a row of 21. Ask your friend to select three card. If the chosen card was not selected, discard and select again. Once selected, retain the three cards, and discard the rest. Next, ask him to select two cards - using the same principle until he ends up with the chosen card.