The Hindu Force
The magician shuffles through the deck and asks the spectator when to stop, when stop is called, the magician shows the spectator the card he/she stopped at, which unknown to the spectator happens to be the original bottom card of the deck.
How It's Done
Hold the deck in your left hand. With your right hand, grab about 2/3 of the bottom of the deck. Rapidly begin to take the stack from your right hand, place it on your left hand and grab a few cards with your left hand, then slide your right hand back. To the spectator it should appear that each time your right hand goes to the left, it picks up a new stack of cards from the middle of the deck, in reality, the magician is only taking cards from the top of the right stack and not adding cards to the bottom. This will be better described once I get the video up.