I think this would have to be a voluntary thing, with the ability to remove it when you have had enough.

 The "Stupid Collar" would be a collar worn around the neck (obviously). This would be a special collar though....it would have little electrodes that would be flush with your skin that would emit an appropriate level of electricity every time you do something stupid. There would have to be some sort of range program involved that could discern between say J walking and going 20 mph on the on ramp to a freeway, but other then that I think there is technology out today that could accomplish this little toy of mine.

 Again I must say this should be a voluntary thing......otherwise, when all the really stupid peoples heads exploded, their families could sue.