This iPhone app monitors your driving and then gives you feedback on how to drive in ways that increase your fuel economy. I remember "Economy" meters in cars back in the 1970's that we basically ignored, but maybe this will be a little more useful.
DriveGain Wants To Help iPhone Owners Drive More Efficiently
from TechCrunch by Steve O'Hear
DriveGain, a new startup that opens its doors today, aims to help users learn to drive more efficiently and, in doing so, save on their fuel consumption. It's founded by Simon East, an ex-Psion exec and former VP, Technology of Symbian who subsequently founded Cognima (ShoZu), and Dr. Phil Dixon, who has a background in racing car simulations and was a recent Vehicle Performance Engineer with the Renault Formula 1 team. DriveGain's first offering is an iPhone app of the same name that, unlike the plethora of sat-nav apps available for Apple's smartphone, doesn't bark out turn-by-turn directions but gives a range of visual and audio feedback on what changes are required by the driver to burn less fuel.