I recall somewhere in the back of my head that the PS2's controller (maybe others, I don't recall for sure) was supposed to be pressure put on the various buttons and left it up to the devs to decide what to do with this feature.
Aside from Silent Hill 2 supposedly having the pressure sensitivity linked to how much damage melee weapons would do were there any other games that used this feature? Or am I just crazy and dreaming up functionality....
EDIT: Turns out I'm not crazy:
Either that or it is a mass hallucination.