David Blaine's Street Magic Trick,  made famous on 

Effect: A name is written on a piece of paper on a notepad by the spectator, the paper is torn off  unseen by the magician, crumpled up and placed in an ashtray.  It is then set alight.

The ashes are then rubbed on the magicians arm and the name of the person written on the paper mysteriously appears.

Preparation : You will need a small notepad, pen, ashtray, lighter and a small piece of soap or wax.

Method: The spectator is asked to write the name of a person or favourite anything of theirs on a notepad.

Then to tear of the sheet of notepaper, crumple it up and place it in the ashtray, where the magician then sets the paper alight.

The magician takes the notepad of the spectator and should be able to see the imprint of the name written on the paper above in the next sheet of the notepad.

Looking at the pad should not be made obvious and some misdirection carried out while he carefully takes the small piece of wax or soap and writes the name on the imprint on his arm or hand  ( this  action should not be visible to anyone ).

The magician can then take some ash from the ashtray and rub it over the wax where it will stick and create an impression of the spectators word to their amazement.

This is a great trick but depends on the magician creating an atmosphere with an entertaining routine and patter about black magic to enhance the effect and create misdirection to allow him time to pull off the trick.