In another example of things you never thought about before, we look at the importance of lateral movement in film. We feel more natural when the action moves from left to right on the screen instead of the converse, even when we don’t notice or can’t articulate the difference. Filmmakers knew that, even before the research that confirmed it.
And it’s not just movement, either. There’s a reason that the devil sits on a character’s shoulder to our left, while the angel sits on the shoulder to our right. This explanation comes to us from Now You See It. -via Digg
I'd be interested to see how it fares among readers of middle eastern languages (often read right to left) or Asians (languages read top to bottom) to see if what feels "natural" to them differs.