On the 20 some-odd remotes I have around the house, I know there are a bunch of buttons on some of them that don’t do anything for my model of whatever it controls. Badr noticed the same thing on his satellite receiver. So he decided to give those extra buttons something to control.
Armed with a little IR transmission know-how, a 16f84a, a transistor array and some relays he added support for controlling his some lights and a fan.
He’s got a schematic and source code up here.