Semaphone was an Android-based app that demonstrated text input via Semaphore, a system of sending messages by holding your two arms (often while holding flags) in certain positions according to an alphabetic code.
How it Worked
Because semaphore uses two hands, the method I demonstrate required two phones, one in each hand, running different apps which communicated with each other. One phone's app was the "Slave", and it reported its position, as read by inertiometer, by Bluetooth (or Wifi? I do not recall) to the "Master" app running on the phone in the other hand. The Master app combined its own position with that reported by the Slave and determined which character, if any, was being signalled by the pose the user had assumed.
In the demonstration video, the only action taken by the Master app was to announce the NATO phonetic equivalent to the character recognized. This was sufficient to demonstrate the technology. It would have been easy to tie the functionality into my "Morse Chat" system, though I suppose it would require boring old textual display (or Morse sounding) of remote traffic, neither of which seems entirely appropriate.
Taking it Further
The next step, in my view, would be to create a small doll device with a Bluetooth transceiver and arms that could signal the remote traffic.
Taking it to the ULTIMATE
The ultimate embodiment of this, in my view, would be to ditch the phones entirely and to give the little doll a camera in his head and have him visually recognize your poses with no electronics being in your hands at all.