At the beginning of the trick, there's a glass full of wine, a bottle, and a funnel. There are also two sheets of thin cardboard and some tape. The performer takes up the wine and the funnel and pours half of the wine into the bottle remarking that this is to ensure that the wine doesn't get spilled as the glass travels. S/he makes up a cylinder using one of the sheets or cardboard and the tape; places it over the bottle "to make sure it's the right diameter"; and then picks it up and places it near to the glass. A second cylinder is made and placed over the bottle, and the first is placed over the glass. Both cylinders are then removed — and lo, the bottle and the glass have traded places! The cylinders are replaced and removed again, and the bottle and the glass are in their original places! Finally, the cylinders are switched and placed: in this case nothing appears to have happened, which is as desired. To prove the lack of skullduggery, the cylinders can be disassembled and demonstrated to be innocent sheets, or for that matter torn up.
The key to this illusion is the bottle, which is most unlike an ordinary one. It is made of metal in the exact image of a wine bottle, complete in all details; but it has no bottom. Inside it, fitting closely but not tightly — the outer bottle has to be lifted from it — is another, as nearly identical in appearance as can be contrived, also without a bottom. (Most important: neither bottle is capped). Inside THAT is a glass, identical to the visible one. The wine poured into the bottle is actually going into the glass, therefore.
When the first cylinder is placed over the bottle and is removed, the performer squeezes gently, sufficiently firmly to lift the outer bottle away. Then, when placing the first cylinder over the glass s/he carefully squeezes it again so as to place the dummy bottle over the glass; when removing the cylinder, s/he allows the bottle to remain over the glass but picks up the second bottle by the same method. Reversing the procedure restores the bottle and the glass to their original appearance.
There is nothing really difficult about this little illusion; the only possibility comes when placing the first cylinder on the table when the outer bottle has been removed. It's advisable to place the glass at the performer's "handed" side — i.e., at his/her right if right-handed. Then it looks perfectly natural to put the cylinder down on that side. It is advisable to cover the table with a cloth that will absorb any spilled drops of wine; this will also muffle any clinks made when setting down the metal bottles. The replacing of the outer bottle is accomplished by switching the cylinders using the excuse that the assistant has to carry them away: the assistant can take them apart or tear them up stage left or right while the next illusion is being prepared.