How about like... you know. HOME-ROW. If the keyboard always ASSUMES you put your fingers on home-row ("asdf - jkl;"). Then you could logically Type ANYWHERE, even in mid-air. After a few milliseconds of idle it revert you back to home row. Any finger not "pressing a key" would be returned to home-row. very simple and intuitive idea to think about. If this motion capture could work, oh how the windows would open, don't forget the bug spray.