I received a package of Tattoo Markers from a Secret Santa this year. The package informs me that they are "BODY ART FOR THE COOL AT HEART" (emphasis in original) and that they are "SPECIALLY FORMULATED FOR DRAWING ON THE SKIN" (ditto). There's black, of course, but the rest of the colors are neon.
I am going to start carrying them around so that I can write "IDIOT" on appropriate foreheads in the course of my average day. I view this as a public service.
Thank you, Gina!