Nickels To Dimes
You place four nickels on the table. After just a moment of expectation you place a magical brass cap over the stack of nickels. You make eye contact with your spectators, place a finger on the covered stack, do a magical gesture with your hand, and lift the brass cap to reveal four dimes in the place of the nickels. The nickels have disappeared entirely. You retreat from the table as your spectators lung forward and examine the dimes and brass cap. You smile confidently... everything is examinable.