I'm currently playing with an EXCELLENTLY constructed effect fro mmy bud Mike (aznofspades), which fits the bill...
Someone hands me a bill, I take out or borrow a coin and wrap it in the bill. The packet is rubbed on the specs palm whereupon they feel the bill vanish and only the coin is left! Then, the coin vanishes just as mysteriously. For the finale, after both hands are shown empty, the packet is found under the specs watch. Very cool!
I have, in the past, used the Jay Sankey T&R bill, which I like a lot, made the bill animate away from my hand across a table top, and performed a quickie effect of my own, Karate Bill, wherein a borrowed bill is balled up, tossed into the air and I drive my bare finger through it while it hurtles through the air.
Also, Greg Wilson's Pitch and Ditch move to transform a borrowed bill into a scrap piece of paper or a coin would be ace!
CL