One example: Certain Sony video camcorders have this exact feature (like mine, circa 1999). They use their IR illumination LEDs to blast the video signal over to a little base station unit so that you can watch your home movies on TV without bothering with wired connections.
The video quality was certainly just a bit less than using the composite connection.
There must be other examples, in addition to the other obvious mention: most fibre optic links are IR.
