Despite it's a Microsoft product, it's actually very nice and useful. A
little pad with a few buttons and connectors for a headset. It's an USB
device, but it doesn't represent itself as an input/HID device:
   HID device not claimed by input or hiddev

I plugged it into a windows box and the USB protocol it uses looks very
simple (see attachment): everytime I press one of the eight buttons, it
sends one byte, a bitmap of the pressed buttons.

What would be the best way to have this device appear in the system?
Having a separate driver/device node? Or is it possible to have a small
driver that would translate the gamevoice commands into evdev messages
and have a new /dev/input/eventX device appear?

I could write something like that myself, my C skills are good enough
for that, I'd just need some advice how to use the kernel USB/evdev
interfaces.

tom