[elhigh]

Eh, just mount the magnets directly to the shaft and pickup coils around them. Voltage would be sky-high but feed it through a transformer to jack the amps up and there you are.

I've fantasized about replacing the distro in my pickup with a racing-style magneto-distributor, which really would make the truck my go-to zombie apocalypse choice. Take out the ignition duties and replace all your lights with LEDs and the alternator doesn't have nearly as much to do.

Of course as I said, it's a fantasy.

[edit]
Oops, I see Daschicken (?) has beaten me to it.