Yes as I thought. Thanks Doyll. I'd seen the little fanmate type one before while researching PWM to DC conversion. I can certainly believe that a fan controller with a PWM channel would be of some use as PWm fans work better on PWM than they do on variable DC.
Still I think its cleaner to use your CPU PWM as if that is getting hot then you need all fans to increase really. Same goes for graphics, if that's being used heavily and exclusively. Few people have anything running of their Graphics card apart from their graphics card, or perhaps even realise it can be done.