Competition in Schools

I've always, being a good liberal, resisted the idea of school vouchers and charter schools--two ideas of libertarian conservatives who argue that introducing competition into the education system would improve it. Other than prejudice (and the fact I'm the child of a school board chair), I doubt its usefulness in the rural areas--there just aren't enough students for multiple systems to work. And I'm skeptical--is a parent going to risk her child's education by trying a new, untested charter system? Seems as if human inertia would work to preserve the existing systems. And the idea that charters might skim the cream has some force to me.

But pieces like Marc Fisher's post here make me doubt my position. The comments pro and con are interesting.