About the size of a miniature ukulele, the Jivix JamStik features real strings that can be pressed, strummed, and bent, as well as piezo and infrared sensors so the Jamstik can be used as a MIDI controller. There’s even a GuitarHero-like tutorial to help you learn.
This has real possibilities. A travel guitar you can fit in your backpack. The JamStik is available for preorder, but be aware that this is an IndieGogo project, not yet a shipping product. That said, this was demoed on the floor of CES, so that gives me hope.