A simple mechanical touch device, with some kind of electromagnetic actuator.
I read about people who put a mobile phone in a fixed cradle, so that when the phone receives a call and vibrates, a band of steel attached to the cradle and with a bulb of conductive rubber on the other end locks into resonance and eventually hits a USB security token.
I read about people who put a mobile phone in a fixed cradle, so that when the phone receives a call and vibrates, a band of steel attached to the cradle and with a bulb of conductive rubber on the other end locks into resonance and eventually hits a USB security token.