The best things in life are free, no question about it. But even if it wasn’t free, I’d most likely buy iTouchMidi, a program for both OS X and Windows that will receive MIDI signals from your iPhone or iPod Touch via WiFi. Pretty insane right? Check out what this guy did with two iPod Touches and iTouchMidi software. He uses the touchscreens mounted to his guitar to control Ableton Live and pull off some Brian Eno-type shit. I’d keep writing but I’ve simply got to try this out for myself. I’ll report back with my findings, Cap’n!