I've re-hosted some variant pages that MrWeasely wrote and used to have on his domain.
Will of the West is the first of the variants. MrWeasely later evolved this into
Wizardry, which retained the main bit - the active mustering - and gave another bonus to the FP.
Action Tokens takes a completely different route, and is also very cool.
In uploading MrWeasely's text, I had to reformat it a bit to work with Google Sites, so apologies for that. They don't look quite as nice as the original versions.