Caleb Larson has created a sculpture which constantly sells itself on e-bay.
It kind of reminds me of this joke I had with my sisters when we were little regarding the Coke "look under the lid" ad campaigns where you looked under the little plastic lid liner and could potentially win a free coke or a luxury boat or other such things. We thought it would be hilarious if one of the possible lid prints was "Sorry! You don't get to keep this Coke". Then, someone would come running from behind a nearby shrub or something and take your Coke from you on the fly.