I am not a geek dot com have posted a review of the Philips Wireless Keyboard. Quote:

    "The keyboard communicates to the receiver via infra red, the exact same way your remote control sends a signal to your television, then the receiver sends a keyboard signal to your PC through the PS/2 connector. Just like with television remotes the keyboard needs to be pointed in the general direction of the receiver but doesn't have to be directly at it. I put my receiver on top of my 19" monitor, and the keyboard in front of it and the receiver had no problem picking up the signal, I was actually surprised it worked perfectly from that angle."