From the "why didn't I think of it" file, leave it to the Japanese to come up with something else so stupid and inane that everyone would want one: light-up smiles. The NY Times reports that these LED smiles are taking the shores of Nippon by storm and consist of - basically - a sports mouthpiece with embedded LEDs that light up. No excuse for getting hit by a car at night now. Check out the accompanying video in the article.
What did you eat to turn your teeth that color?