Interesting! How similar is the 37x0 hardware? Do you know if it's possible to solder in a microphone or maybe is there a socket on the PCB of 3750/60/90?
EDIT1 (27Oct11): Sorry, got carried away. That's a hardware question & doesn't really belong here. Ingore it.
EDIT2 (06Dec11): turboccc's tutorial for adding a mike to 3750 is at [Only registered and activated users can see links. ] in this thread.