[bradleyland]

I found some software that does just this and a lot more. Unfortunately, it hasn't worked terribly consistently, and the voice quality when using my MacBook Pro as a mic/speaker isn't passable. I really love the ideas presented in the app though and am holding out hope that he continues to develop it.

http://www.sustworks.com/pa_guide/index.html

[projct]

This is due to the Bluetooth Headset Profile (HSP) using a terrible codec[1]. There's nothing you can do about that.

[1] 64K PCM or CVSD http://www.swedetrack.com/images/bluet03.htm