Also from EvilMadScientists comes this wonderful clock, combing a plotter with Buddhaboard, which is a dark background with a gray ceramic cover which is transparent when wet, so what is drawn on it with water disappears as it dries.
This would be cool to have in a reception or such. (In a place where the noise isn't a problem.)
It is based on the equally kool WatercolorBot:
Invented by SuperAwesomeSylvia. (Man, kids today are scary.)