Actually, search will not help at all, since this subject was not discussed much. You might be thinking of the "[Announce] Faster kinetic scrolling in app menu (PR1.2)" thread, but that only changes scrolling speed in one place, so it is not really an answer to the posted question. The answer is: Most kinetic scrolling widgets you see probably use hildon library for kinetic scrolling. This library is free software, so you could change global scrolling parameters by changing this library.