Presto's personal card through window routine is superior to others in that it can be performed -- with a borrowed deck of cards -- almost anywhere there is a window.
A deck of cards is freely shuffled. The spectator picks a card and returns it to the deck. The magician makes a magical gesture, take the top card of the deck, and throws it through a nearby window. The card can easily be seen outside, on the ground, face up -- it is the spectator's selection.
The cards are really shuffled and the selection is honestly lost in the deck. The magician uses standard slight-of-hand techniques (Presto prefers to use thumb-indexed estimation and a dribble half pass) to bring the selected card to the top of the deck.
Using clever patter to cover motion, the magician retrieves a custom-made "window plate" from some hidden location (Presto uses the bottom of a shoe) and palms it. The window plate is a thin sheet of depleted uranium a tenth of an inch thick, cut to the precise shape of a playing card, with edges honed to razor sharpness.
When the magician takes the top card off of the deck, double-sided tape is used to adhere it to the window plate. The plate and card can now be shown by a magician wearing thick gloves as if they are the card alone.
With a little practice and some significant arm strength, the card with plate attached can be thrown through pretty much any window, including office windows. Note, however, that it will merely embed itself in bulletproof windshields and the glass at Sea World-style aquariums, and this is less than desirable.
The magician needs to make sure that the spectator does not reach the selected card first. Anyone other than a trained professional who picks up the card and window pane will not only see how the effect works, but also might lose a couple of fingers.