I can manually toggle the A2DP on or off of my Jarba BT530 headset (on my Droid) by going to Settings->Wireless & networks->Bluetooth settings->[click and hold my headset] Options...-> [under Profiles] Media [uncheck]. By doing this, I can still use my headset to answer calls, while music is played through the speakers via the headphone jack. I would LOVE a toggle button that I could place on my screen to toggle this for me. I would do this myself, but I know nothing of coding, and even less about Android coding. I really hope someone takes up this request.