Blackaddr, Forgive me if this is inappropriate for this thread, but I was interested in the idea of integrating a teensy directly into the body of an electric guitar, where I could use 6 analog signals from a divided pickup (like this
http://www.ubertar.com/hexaphonic/index.html) in order to perform pitch detection on each string for converting the notes played on the guitar to digital notes that the Teensy can use for a six-voice polyphonic synth instrument generated by the Teensy Audio Library. You could also convert the signals to MIDI and control external devices and whatnot as well.
You could then have a single mono or stereo output from the guitar, and on the guitar you can have pots and switches for controlling the dry guitar signal, the synth signal, and the effect signal that gets applied to both the guitar and synth signals.
I know this is not exactly the scope of your project, but I wonder what it would take to have that sort of capability. The guitar's body could be routed out to act as the enclosure for the onboard device, and could be powered by a rechargeable lipo battery.
The reason why I'd want this sort of setup is to avoid having to use something like a Fishman TriplePlay or the Jam Origin Midi Guitar software which typically requires you be hooked up (wirelessly or not) to a PC/Mac while playing.
With this setup you could upload simple patches or use basic the oscillators and have an onboard guitar synth, effects, as well as the normal guitar.