I'm sucessfully using a Marmitek StereoControl infrared receiver to do just what you want. Certainly not the most advanced bit of kit, it's powered by a 9v battery, and sends the signal along 2 wires to 2 sensors you stick onto the receiving devices, but it works really well.
See here for the sort of thing:
http://reallycleverhomes.co.uk/acata...extenders.html