Some might say the cord on the Guitar Hero "controller" is more realistic, simulating the cable on an electric guitar. Lucky for us TheDude06 isn't one of them. He's done the due diligence, and posted it all on Make's forums, so we can reap the rewards. His instructions make the project seem pretty doable, if you have a little patience and a soldering iron. He says, "If you dont mind possibly trashing your contoller, there is only minimal electronics knowledge required to do this "mod". i didnt do anything more than run a wire from the guitar switch, to a pad on the controller. The only parts required were a battery holder, and a switch."
Sure it costs a couple rupees, but if you have a tendency to slide on your knees or jump off the couch while rocking your face off playing, you're probably sold on the idea already.