Home Built Hardware
NetHomeServer can use the speaker audio output to send protocol signals for IR or Radio (RF) protocols. To actually send them as IR or RF, you need some kind of additional hardware that can transform them. In the same manner, the microphone input can be used to decode such protocols, and again you need some kind of hardware to receive them. Often you are already using your sound card, but there are very cheap USB sound cards that you can use like the one in the picture below:
I have collected some examples of transmitters and receivers that I and other users have built. If you have built a good interface for transmission or reception, you can mail me the descriptions and I will publish them here.
With a generic 433.92MHz OOK transmitter connected to the speaker output and the protocol drivers in NetHomeServer, you can control most of the radio controlled remote switches sold in Europe, for example: Nexa system, Chacon or Elro AB600.