[Hampshire] USB power control ?

Hi,

Does anyone know of a utility or API for controlling the power to
external USB devices. ie. Some way to tell a hub to disconnect the
power from one or more of it's ports.

I'm sure there must be a standard mechanism but can't find it.

If not come Tuesday we'll be writing our own but it realy does
feel like reinventing a wheel.
-- 
        Bob Dunlop