there is an interesting discussion is picking up steam over in the discussion forum on Skeuomorphic Design. Long time poster "Slippyfish" defines a skeuomorph as a derivative object which retains ornamental design cues to a structure that was necessary in the original. This really ranges from things like ornamental shutters on a new home that don't shut, to the five bolt pattern on Ducati gas caps even though only three of those are now functional, to the shapes of modern shoes which have evolved from cobbler's wooden foot forms and have little to do with the anatomical foot, but instead more to do with our perceptions of what a shoe should look like.
An area this is happening at a rapid rate is in the convergence of physical and digital experiences. Think of how many apps on you iPhone have skins that look like physical buttons. Sometimes the skeuomorph is a design cop out, and sometimes it helps us bridge the gap between experiences to intuitively know how to use something without any experience. Would Guitar Hero be any fun with out a guitar shaped controller? To that end, Sean brings up the iPad DJ app, which mimics a real turntable visually. Its not what you need, but its what you want!
Check out the discussion and weigh in > HERE.