It has been my impression (and I have used it quite a lot) is that Naturally Speaking can be used to control a PC hands free - but you may need the professional version.

I would be interested in the ways that NS fails to be 'hands free'

From my (admittedly limited) investigation into Naturally Speaking as an aid against RSI, the software indeed claims complete hands-free use of the PC, but is made much easier with the Professional version, which allows you create custom macros, making common tasks quicker and easier to do.

Of course, this is only a part-solution because I've heard reports of issues with getting even the Pro version to behave nicely with Firefox, despite working quite nicely with Thunderbird.