Apple's closing out the new application talk today at WWDC with a demo from Line 6 and Planet Waves, who have joined the Cupertino-based company in order to give your iPhone the ability to control your guitar and amplifier. Sadly, the wireless communication between the Line 6 Variax guitar and the iPhone on stage had some issues, though the folks assured us we could see more later on at Line 6's website. If this thing manages to function, it will also let you re-tune your six-string and change models on the fly. No word on price or availability just yet, but we'll let you know if either of those factoids appear.