NXT Dial Remote Control
1. Simple and sturdy, low part count
2. High "on-center" stability (whenever you take your hands off the remote, the robot should stop, no need to find a center position)
3. The motor power is always applied very progressively (no jerking on or off) with easy fine-control for accurate small movements, but you can still get full power.
For these, I was willing to give up the ability to drive forward and steer at the same time (only straight and pivot turns are available), or drive and operate the 3rd motor at the same time.
The mechanics is very simple, basically just a single motor attached to the NXT. You choose one of four functions to control by pressing one of the 3 NXT buttons (or no button), then use the motor (dial) to apply power/value to that motor/function. The key is that it is the speed of the dial, not it's absolute position, that determines the power applied to the motor. This gives you a nice progressive feel, kind of like an iPod wheel, and the hands-off stability in any position.
The remote can control many different types of robots/machines, many with no modifications to the program (typical 2-motor vehicles with optional 3rd motor), and I also included a wired remote variation for those with only one NXT. All programs and instructions are included. The building is very simple, the programs are not so simple...
Here is a video of the remote in action: