That's actually a sort of interesting thought.
I'm not sure if you'd get much out of such a self winding recharge mechanism like that though, as those self winding watches basically rely on your arms swinging as you walk/jog/run around.
Still a nifty idea. I could see one designed without any battery at all and just a little flip out hand crank handle instead. Not like it should take more than 5 seconds or so to light a doobie, so it wouldn't be all that inconvenient, and you'd never have to bother charging it..