I’ve just read that the Nunchuck from Nintendo uses a I2C protocol !! could be fun to have such device in your modular. Obviously I ordered two from China !
all details here (yes again and again that bloody Arduino !) : ZX-Nunchuk_e.p65 – inex-zx-nunchuck-datasheet.pdf
the drawback is that I need at least 5 10bit DAC.