Hey all,
I spent a few hours last night breaking into the Bliptronic 5000, provided for $43 from Thinkgeek. Reviews are everywhere, but the consensus is.... the synth sucks, and a comparable button-matrix in an enclosure would cost 4 times as much.
So... I've done a little reverse engineering to determine the pinout and control mechanism here:
http://www.straytechnologies.com/bliptr
utton-pcb/
It looks like this will mate up nicely with an arduino to make something in the monome/arduinome family for under $100 with the enclosure.
Drop me an email wil [at] straytechnologies [dot] com if anyone else is working on this.