Folks - just bought a Rii mini bluetooth wireless keyboard for £25 and so far so good. Very neat size, very responsive, has blue backlighting if you want it on, obviously not designed to write large emails but for general navigation of XBMC etc and web browsing it is excellent. Good range also, I can sit 20 feet away from the screen and it works fine. Have yet to build my HTPC but got this ready for and tested on home PC.
This didn't last long. Started behaving odd, battery life lasted only an hour or so on a full charge. Cack basically. Will be returning.