The crocodile and the toothbrush

The toothbrush uses a colored end to help inform children if they are brushing with the right pressure (green=good, red=too much), then turns blue when you have brushed long enough (two minutes).

Even more interesting from a social condiditioning perspective, the toothbrush interacts (via RF) with a silicone crocodile that will remind them to brush if they forget. The crocodile maintains a steady lifelike breathing motion, but if the child forgets to brush it will slow down until it eventually stops. The only way to re-animate it is for the child to brush their teeth correctly. (from We Make Money Not Art)