I'm building an intelligent headlight system driven by a home-made alternator. I'm figuring it will have as much other stuff as I can cram into it before I finish. It will probably become a complete dashboard with all kinds of useful (useless) indicators.
http://www.chesterfamily.org/Projects/BikeGenerator/V2ControlSystem/
http://www.chesterfamily.org/Projects/BikeGenerator/