One of the coolest thing about the iPod is the twist-and-press software interface that allows you to navigate through a hierarchical menu system. What’s surprising, is that, iPod is not the first place we see this kind of interface. Saab’s automotive SID (System Information Display) had been doing that for at least 5 years to my knowledge. Take a look at the pic below. The “twist nob” you see can control the “scrolling” of the menu items. Press the “twist nob” result in a selection state. The only missing thing (in iPod’s term) is the slick “side sliding effect” you see.