Yes, they are. It's what changes the device from a standard computer (with an indirect interface) into direct manipulation of objects on a screen. With Palm OS-

Yes, they are. It's what changes the device from a standard computer (with an indirect interface) into direct manipulation of objects on a screen. With Palm OS-style scrollbars or desktop scroll wheels, you are manipulating an object that affects something else. With iOS-style scrolling, there is nothing to learn. That's one of the biggest issues with Android (and, conversely, one of the advantages of Windows Phone and iOS): because Android has not been able to match the fluid scrolling and realistic physics, it breaks the illusion of physicality that the original iPhone managed to first create in 2007.