I found arduino while working on a project for my company. I just realized what gem this board is for rev heads like me. With a $40 board and easy programming language you can controll a lot of stuff on your car. Anywhere from closing your windows at over 150KM/h to having a kick ass NOS controller(rpm window selenoid controller etc). Also I think the PWM controller can controll injectors. While using it as a standalone ECU would not be easy it could easily be used as an alcohol injector controller. You could have some really smart controll of the injector(intake temp, rpm, knock sensor). Let your imagination run wild.
Thanks the possibilities are endless here.