I think someday I'll give a try for stepper motor generator. Just for try or rather fun. I have idea stuck in back of my head to make a windmill. The only concern can be shaft thickness to cope with a rotor but tooth belt reduction and rotor on its own shaft can sort this problem out.
Gary: my neighbours got used to some weird noises blasting from my backyard and I can only hope a stepper motor generator won't over-exercise their patience :)