Really? My device didn't come with any software, so I figured there wasn't any. I'll have to do some checking - and the Windows volume thing changes in much smaller steps than the OSX one, so you have to press the button much more for any result, so some drivers would be nice.
EDIT - okay, as part of the Boot Camp installation, it produces a cd with Windows drivers for a bunch of Apple stuff. I haven't pulled down the installer yet, so I don't know if it's possible for me - with only AMD PCs and non-Intel Macs - to run the install enough to get to the CD making stage. Can I download the included drivers somewhere?
EDIT2- I downloaded 'applekpro' while I'm waiting for Boot Camp to download (I've been capped to kb/s

). It seems to do almost everything I need - providing a print screen key, making the eject button work, etc. However, I'm still looking for one of those on-screen volume display things. I've seen PC keyboards with volume knobs display OSD-style overlays when the volume controls are used, and that's what I'm after.