Dunno if you've see
Rocksmith
It's guitar hero/rockband but with a real guitar. I believe you can play a simplified version of it or use it as a tool to learn how to play the guitar. I don't know how well it plays, but I remember coming across a similar version years ago while researching for a project where I made a similar program albeit much simpler looking (but mine didn't need it's own special interface!!).
I guess the one major drawback to Rocksmith is the cost of not just the game, but also you need to buy or already own an electric guitar.