They do exist !
Well - sort of anyway - I have a Media Centre PC Cube type PC at home under my Plasma, to browse the web, listen to my iTunes etc, I Purchased an Infra-Red keyboard with a built-in "nipple mouse" and it works just fine. However - and it is a shame for the Mac, it has PS/2 keyboard and mouse connectors so is useless for the Mac. Once one arrives as a USB version (and I will keep looking on this forum) I will sell the PeeCee and get a MacMini instead. Just so you know I got the Keyboard on Ebay (brand new) for around £20 - that is around $35 I think in USD
Good Luck !