Mr. Micawber: your omnipotent forefinger? Do you mean you use it for all the keys ;)
Grammar Geek: Although the classical technique commands to use the little finger for that, I also find it more comfortable to press zero with my ring (Nameless in Russian) finger. Maybe my little finger is too short, so I need to shift the whole palm to help it reach the destination key...
Note sure which finger is the pinky... The little one?
As for me, I incline to use the litte finger for thr CTRL and Windows keys, and the ring finger for ALT...