There are numerous gimmicks out there, most of them using electronics or magnetics in order to accomplish a relatively simple bit of business.
You might want to track down a copy of Jerome Finley's "Thought Channel" however, I can assure you that it is well worth the price as well as the time you will need to invest when it comes to making it happen and several alternative scenarios for taking advantage of the same
improvisational skill set.
I do find it humorous though... how the name to some noted yesteryear effects have been revived; "The Sixth Sense" was originally a simple cloth bag in which six or so marbles were used, one of which was different from the rest. With the bag behind him, the mage would invite a group of volunteers to withdraw a marble and hold it in their fist. Only the person holding the odd sphere would know that he was it (for real). The marbles would then be replaced and by way of "psychometry" the mage would be able to discern who in the group had the odd marble.
I think I got this thing when I was about 13 or 14 and performed it so often that the poor bag was worn thin. But even in the day it was quite a pricey piece.
