keynav turns your keyboard into a fast pointer mover.

You select a piece of the screen. The screen is initially wholly selected.
One move will cut that region by half. A move is a direction: up, down, left,
and right.
Once you're done moving, you simply indicate that you want to move. Boom,
cursor moves.

keynav is geared towards selecting a piece of the screen very quickly.
You are selecting a region by cutting the previous region in half. This gives
you logarithmic scaling. High resolution screens incur about the same number
of moves to select an area as smaller screens do.
