The folks behind the Lens/Focus Shifter (official name still pending) have decided to throw away the traditional follow focus design for one that is both simpler and cheaper. The Shifter simply straps to the lens allowing you to control your focus or zoom without need of a rail support. While I’ve seen designs similar to this, what really makes the Shifter unique is the marking disk. It allows you to use the Shifter without sacrificing the ability to mark multiple focus spots.
The Shifter is currently seeking funding through Kickstarter. Jump over and pick one up.