Our friends over at Gear Gods discovered weirdest thing I've seen in a while: the Fretpen. It's basically like a mini djentstick.
Check out the video below for a full demonstration because it's kind of difficult to explain, but the basic concept is you plus this little guitar into your mobile device, set up what notes you want on there, pick a tone and then rock. It seems like it would be an amazing thing to at the very least mess around with and it's totally endorsed by Queensrÿche drummer Scott Rockenfield and former Megadeth guitarist Glenn Drover. The other interesting thing about the fretpen is that it appears as though you can program different chords on it as well to mess around with, which is great for when you can't access a real guitar.