Just thought this might be of interest here: I have gotten a logitech diNovo Mini keyboard (which also incorporates a touchpad) and it is perfect for being able to access all features of my HTPC. I'm running fedora Linux, and after a fun trip through the kernel, I even have the touchpad working. The full story can be found here:
[Link: home.att.net] (naturally, it also works on Windows XP with no problems - I don't have Vista, but logitech claims it works there as well).