Ahh, basically a pipe with a carb, only much larger.
Yeah, the extra oxygen gets things rolling quick. Another way to get high fast is Poppers (you pack tobacco into the slide of the bong to hold up the weed (there's no bowl used here), burn the weed, and inhale the smoke, and when you get to the tobacco, breathe in really hard until the tobacco popps into the bong, causing a rush of air and smoke like when you open the end of the steamroller)