In today's NYTimes, there's a quick item on Tooth Tunes, the $10 toothbrush from Tiger that literally plays songs in your head. Dentists will agree that "two minutes" is the only imperative for cleaning your teeth (you could basically brush with a stick, if only you did it for two minutes), so compelling kids to listen-'till-the-end-of-the-song is particularly ingenious. And there's no speaker--the sound vibrations are transfered through the bristle head to the teeth to the jaw to the armbone, etc. But: The battery isn't replaceable--you gotta throw the thing away after 6 months. (Of course, you could argue that bacteria-wise, you should be doing that anyway.) Ugh. Can somebody please solve this problem? Or should we just stick to the stick?