From the November 2008 issue of Entrepreneur

Want to make your commute more fuel-efficient - and fun? Then take a bite out of Kiwi, a 2-inch-by-3-inch device that plugs into your car's on-board diagnostics prt in 1996 or newer models. By measuring acceleration, smoothness, drag and braking, the game-like program calculates your fuel-efficiency to help you improve MPG by an average of 20 percent. It tracks gas and money saved and also scans potential probles should an engine check light come on.

PLX Devices
Kiwi

plxkiwi.com
Price:$299