A few ideas:<p>- Exhibition window with the upper part of the window being a speaker.<p>- Surface on the iPhone that isn't touch sensitive could be a speaker glass.<p>- Car windows becomes huge speaker.<p>I love inventions :)
Beyond the question of the audio speaker, we're talking about the ability to conduct ions and that itself has a lot of applications for conductivity. In particular, it means that you could create interesting safety devices and finally have really interesting wearable technology. Honestly, nobody wants wires, but people are okay wearing gels and spandex for their devices.