[Lindsay Williams] has come up a novel way of constructing custom physical inputs for your programs. SenseSurface is a viable alternative to building a new interface for each application. Simply place the dials, buttons, and sliders on your screen wherever you want them.
A sensor board, placed behind the display, picks up the signals from the inputs. The only limitation to the number of inputs available is the size of your screen. Inputs are held on magnetically, and have a low friction backing to avoid scratching or gouging your screen.