Nice! It really looks great. A little bit see-through when looking at it with my magician's eye (only because I've seen that particular method used elsewhere--I can't remember where, but I've seen it used before), but to a spectator that would be marvelous! Adding a switch from a coin to a key was a nice idea.
I'd be interested to see B's take on this method, such as the effects he uses it for, and his clean-up. Also his get-ready, as it'd be mighty ballsy to set yourself up for the effect right in front of the person (in a way that doesn't look obvious).
Can't wait.