I, The Rival Wrote:Bhopping, if done right, combines the speed of running with almost the same amount of silence as walking (sometimes you get the little jump sound, but its harder to place where they are).

depends on the floor i must say... on cs 1.6 and cz, you can do sth similar called bunny jump.. by pressing ctrl for an instant twice, repeatedly... but valve remove this feature on source, idk why