If you haven't seen Monkey in the Middle your missing out. It's one the best "Sandwich" effects out there. I put a video of it on my site www.angelfire.com/magic/magic4u
The effect is have "any" card selected, Signed, and replaced. Show two indifferent cards freely, place them on the top and with a wave of the deck immediately spread and show the signed selection caught between the two indifferent cards. I didn't sign the card on the video as I just purchased the deck and didn't have spares around.