Most people create reward systems for themselves when they manage to achieve their goals. A friend does the opposite. He set up a self-penalty system for punishing himself when he fails to achieve his goals. His penalty: burning 20-dollar bills. He keeps evidence of the penalty on his fridge as a constant reminder.
He reasoned that when the system is as harsh as burning one's own money, those goals are more readily achieved - for example, it serves as a great way to quit smoking. Each time you smoke a cigarette, you must burn a twenty-dollar bill.
He suggested that putting physical evidence as a penalty reminder is not something new: in the old times when the penalty of crime was getting one's head chopped off, cities used to place those heads on spears and placed at the town square to remind citizens to not commit crime.