I don't do much mentalism. I wouldn't do any, except that I have a wonderfully charming little vintage prop on a mentalism theme. It's unusual, and I like to show it here and again.
I recently had occasion to present it at the New Mexico Arts and Crafts Fair. After making some mind-reading-related remarks, I called up a spectator for help with the trick, and as she made her way to the stage, I was thrilled to note that she was wearing a name badge. I would be able to begin my mind-reading demonstration by confidently calling this person by name. She crossed the stage and I greeted her with an air of warm familiarity. "Hi! Are you..." - I nodded knowingly and got the glance - "Volunteer #115?"
The effect I had anticipated was lost, but a witty exposure of the methods of mind-readers was obtained.