Some of you have likely ridden in a car equipped with a blue tooth system that automatically connects your cell phone through the speakers in the car and allows you to talk into a microphone which is (I think) installed in the rear view mirror. This allows you to conduct a hands free conversation with anyone who calls (from any service, i.e., Verizon, T-Mobile, etc.) your cell phone number.
The application that I have developed is similar in that it automatically connects your cell phone conversation to your PC's speakers and microphone so as to allow you to conduct a hands free conversation.