Yes, anywhere "further down the wire" from the receiver, and it's an ordinary keyboard, they even work in BIOS.
The only gotcha is obviously if it's a keyboard with millions of bells and whistles that only work in windows with the drivers installed (there are some top line gaming keyboards that fail basic keyboard functionality, useless in BIOS, that sort of thing, there's a thread about it somewhere on here), you won't have all that stuff available without a bit of tweaking.
Having said that, as with most things in Linux where you have to make a bit of an effort, the possibilities are far more vast than if you were using the "easy" windows equivalent. For example, you can make those hotkeys for web/mail/sound etc do virtually ANYTHING.
