Well, I must admit, I hadn't until I came across this one. Isn't it cool?
I do play guitar myself, just a little and quite frankly I was impressed and intrigued by it. It is endorsed by some big name guitarists like John Oates of "Hall and Oates" and it is a full size premium guitar with a great full sound (check out the video on the amazon page).
It is a Voyage Air Guitar and guess what? They even make "foldable" electric guitars too!
Every guitar includes a customized back pack style case enabling you to take your music anywhere you go!