Do you have a link to that Apple study? I find that very exciting and never heard about it before. Though it would mean, that me and many other geeks are plain wrong about their preferred input method.

You might be interested in DiamondTouch [1] which allows multiple users on one touch table. I tried it out at a presentation at the MediaLab in Nov 2010. The trick, if I remember correct, is that the user sits on a special chair. The chair, then detects an electric connection between the user and the table.

[1] http://en.wikipedia.org/wiki/DiamondTouch