I've used this trick in Canadian currency and can tell you for a fact that it gets great reactions.
You hold out two quarters in each hand and give the spectator a coin of which ones will be used.
Give him the quarters and have him try and balance one on the other. This is very very very very
difficult to do and no one will ever be able to do it. Tell them to watch as you balance the quarter
with ease. Not only that but you slowly but carefully spin the quarter on top of the other one. This
will blow them away. As stated above, this is a great trick for beginners and requires no skill at
all.