[rjacob]

How about a cruise control designed for hypermiling? Someone could probably modify a cheap after market cruise control to be more fuel efficient. Maybe have it recieving data that the scangauge gets. Then write a small computer program to read the data from the port, and control the throttle. It could use info like rpms, speed, throttle position. And do easy accelerations. It could tweaked to maximize the gas milage, but with the ease of a cruise control. It can maybe even learn. I have a programable thremostat at home that learns the heating characteristics of the room. It learns that if it sends x amount of power for y seconds, the room temperature will by z. That way it can keep the room temp pretty consistent. The cruise control could learn the characteristics of the car.

The electronics is beyond me, but I could probably do the programming stuff.