[Make This is a series I introduced last week where I offer up ideas that anyone is free to run with if they have inclination to actually build the necessary props.]
Here is what it would look like.
You ask your friend if he'd like to see something totally bonkers. "You can't tell anyone about this. I'm not supposed to have this and I'm certainly not supposed to show it to anyone."
You pull out two glasses from a box and ask your friend to take a look at them. The glasses are slightly different in some way. Maybe one is a little taller or a little wider than the other.
"It doesn't look like much, I know, but I need you to be really careful with these glasses. They cost like $6,000 a piece or something crazy. I have a friend who is a physicist working at the Brookhaven National Laboratory in New York and he's letting me borrow these for a few days because he knows I'm fascinated with stuff like this."
You pull out two half dollars and put them on the table. You ask your friend to take a look at them and drop one into each glass. He does.
You pick up one of the glasses. "This is the sending glass. You'll notice it's shorter than that one. I'm going to try and explain this but I understand maybe 5% of how this works. These glasses are specially constructed down to the nanometer, which is one billionth of a meter. And they're constructed in two similar but opposite ways. My glass is made so that the sound wave that comes off the glass when a half-dollar is rattled around inside, is exactly opposite in frequency to the sound wave that comes off the half-dollar itself. Your glass is constructed so the sound waves are identical and in sync. So my frequencies will cancel each other out, and yours will double."
"I know that just sounds like... 'huh? what?' but I'll show you what happens in practical terms."
"Take your glass and hold it like this. In a second I'm going to have you shake the coin in your glass, but I'll go first. Watch."
You pick up your glass and start shaking the coin in the glass. You can see it and hear it rattling around. One moment it's there, and then "poof," it's gone. You hold the glass upside down. There's no more coin.
You tell him to pick up his glass and start shaking the coin inside. He does and after a couple moments another coin pops into existence in his glass and two coins can be seen and heard rattling in the glass.
You indicate he should stop shaking the coins and dump them in your hands. You set the coins on the table. Your hands are empty. Everything can be examined.
Project Name: Beam Me Up, Scotchy
Required Skills: The ability to construct gimmicked coins
I'll rush though the basic handling because it doesn't make a ton of sense to write a full handling for a trick that doesn't exist.
The coin that vanishes is a magnetic half dollar. During the shaking it gets attracted to a PK Ring, PK Blista, Enigma gimmick or something else in your hand that's holding the glass. You turn your hands over showing nothing in the glass and slide the glass up and away from the coin now secretly in your hand.
The other coin is the special coin that would need to be made. Essentially it's a scotch and soda type of gimmick. This trick is based on the technique of dislodging the insert from the shell of a scotch and soda gimmick by shaking it in a glass.
But you need a gimmick that doesn't exist yet (I don't believe). It would need to look like a normal half dollar when nested and two half dollars when the insert was out. The "two coins would only be seen in motion or at the bottom of a glass, so you don't need perfection in that part of the illusion.
So you'd need something like this: The shell part of the gimmick would have the head of a coin on top and the tails side of a coin printed on the inside of the shell in some way (it could probably just be a sticker with the tails-side of a coin on it, unless there's some better way). The insert of the gimmick would be the tails side of a half dollar on both sides.
When assembled, the coin would be completely examinable. When dropped in a glass and rattled around, it would split into its component parts. It would be a spontaneous appearance of a coin that could be seen, heard, and felt by the spectator as he shakes the glass.
Obviously the spectator can't examine the coins immediately. But you could have him dump the coins in your cupped hands (with the other half dollar in your right fingers, blocked by your left hand on top). Then, as you examine the coins yourself ("hmmm.... I can't even tell which is the original") you could quickly re-shell the gimmick (the double-tailed insert makes this quick so you don't have to reorient the coins as much). Then just turn both hands palm down and place a coin on the table and you're clean.
Now bust out your CNC machines, bitches, and make this for me.
[Thanks to Joe Mckay for reminding me of the idea of rattling a nested coin gimmick in a glass to get it out of the shell and pointing me to a usage of it that was done in an overt way.]