What really distinguishes a guitar player is his or her ability to make a guitar sing. So, I think it's a natural thing to take songs you know by heart from a vocal standpoint and learn to sing them on the guitar. I first started to do this by modifying the Playstation game Karaoke Revolutions' microphone to allow me to plug my guitar directly into the game. This trick still works on more modern games like Rock Band and Guitar Hero. Here are some videos of me in action playing guitar to the game.