Duel reality effects in magic are some of my favorite, and it was only upon recent reflection that I realized one of the first I learned (though certainly never performed, if that is even the right word) is one presented by R. Paul Wilson in "The Real Hustle."
As a quick aside, I think most magicians can learn more from this series than they can from the majority of magic books. Although it teaches basically no moves, it is filled with example after example of the psychology required to lure somebody into a moment of astonishment and surprise. Obviously in the show's context this surprise is bad, but the concepts can often be used in magic effects as well.
The particular effect I was reminded of was his BH Wallet Scam. You can watch the video (it's about 6 minutes) to see the basics, but the core concept is one of dual reality. The performer (or con man) sets up the audiences (the marks and the waiter) so that they will interpret his actions, and more importantly their own actions), in two completely different ways. Not only that, but it shows how far you can get with a very, very small duel reality. If Wilson can get an entire meal out of a single waive, imagine what you can get in a magic context.