Here's a clean version of the ByteBeats circuit we built last Sunday. I used a Teensy-3.1 instead of a Teensy-2.0, but everything else is more-or-less the same. (I added some capacitors on the power lines, a volume control and a speaker instead of the headphones, but it's all minor changes that anybody at a Dorbot meeting could help you with. Or email me, I'll go through it with you.)
The ByteBeats workshop went pretty well: everybody left with a working circuit, although there were some hiccups along the way.
I hope you all enjoyed the project. Keep in mind: the same circuit can be used for a bunch of different audio hackery by changing the software. For example, I wrote a program to produce sine waves at regular musical-scale intervals. It's a short step from there to playing MIDI, I imagine.