After a good bit of pussyfooting and finally finding the necessary amount of can do attitude, Tait from decided he would indeed be able to modify his prosthetic finger to include a Bluetooth handset.

Tait went about his business starting from an ear-mounted Bluetooth module, then extended the volume button with some plastic and put it under the battery – and with the help of some wooden matchsticks to stabilize it or squeeze it or do some other randomly vile things to it, he can squeeze the hold thing to adjust volume.
He then molded a hollow plastic finger to hold the entire contraption, and a thumb ring provides room for a speaker.

Now, I’m not saying this concept won’t catch on, start being manufactured by someone like Sony or Nokia, and become a worldwide sensation, but it won’t.