If this isn't solved yet I bought this particular trick from the New York New York Hotel in Las Vegas. There was a magic shop, might still be a magic shop? behind a disguised bookshelf in the main casino.

The trick is actually pretty simple but if you perfect it, it looks awesome.

The trick works as follows, little bit of wax behind your earlobe, attach a fishing wire about 2 feet of it is enough, put another piece of wax on the end. When you take a dollar or a playing card from someone you attach the wax to a corner, he does this when he folds the bill, then you leverage the wire between your fingers to dangle the card/bill. When you hand it back to them scrape off the wax for them to examine.

https://www.youtube.com/watch?v=WqKKaZ_TAHQ

this video doesn't show how its done but the performer is much less smooth making it more obvious.