Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects...http://www.google.ca/patents/US7623667?utm_source=gb-gplus-sharePatent US7623667 - Electronic device accessory with ultrasonic tone generator
