Thanks for the info.
I have my iPhone in my bag and use the headphones for music. Often calls come in and I have to fish out my iPhone, unplug the headphones, and after the call, plug the headphones back in and put the phone away.
I figured if I could just take the headphones off my head, take my bluetooth earpiece out my pocket, have the phone call, hang up, and put the headphones back on, it would be awesome.