Today’s invention is a screen management program which causes software objects (such as folders and documents) placed on a laptop desktop to behave as if subject to physical forces (primarily gravity). This would cause items to slide to the bottom of the screen unless ‘pegged’ in place.
Similarly, ‘paint’ applied to a graphic would drip downscreen in a physically real way.
All of these simulated phenomena would be influenced by the angle of the screen to the horizontal (ie the farther from vertical, the slower the movement).
This seems very possible with the ubiquity of accelerometers.