A shop receipt can be shown front and back and then in the action of folding it and turning the folded receipt over and then unfolding it turns into a note of your choice which can then be handed out.
What you get
A gimmick and a password for online instructions
What I think
I am a big fan of most of Nick Einhorn's material so I saw this and immediately hit the buy button. I think it's workable, takes up minimal wallet space and the fact that you can hand out the note afterwards is useful. You are dirty at the end but the heat will be on the note initially so you've probably got a good opportunity there to clean up.
Takes seconds but not in front of an audience.
I have a slight concern about the edge of the note flashing but that's probably me being too picky,