Demitrios Kargotis unveiled his Mr Whippy machine at the Ars Technica festival in Linz. It's a self-serve frozen custard machine that doles out portion sizes based on the amount of misery it detects in a voice-stress analysis. The sadder you are, the more ice-cream you get.

Employing voice stress analysis of the user's answers to specific questions, varying degrees of unhappiness are measured and the counteractive quantity of ice cream is dispensed: The more unhappy you are, the more ice cream you need.

Link