Oh hies, Apple fanboy. Did you know that your precious iPhone can now stream your music to a Bluetooth headset? That is, of course, you upgraded to version 1.1.1 and your iPhonez wasn't h@ck3d, which by the way works fine now even if it was bricked. Learn how to downgrade from 1.1.1 to 1.0.2 here and then you can bring back your bricked iPhone to life.
Now back to the important stuff. The latest software fails to disconnect your audio stream from your Bluetooth headset when exiting Visual Voicemail. In fact, it streams every sound your iPhone makes. So take advantage of that glitch by connecting your BT headset and selecting ‘audio' from the VVM interface and you'll be presented with the option to ‘change audio source'. Your choices should be ‘iPhone Bluetotth Headset", "iPhone", or "Speaker Phone". Pick the first option and your set to go with streaming audio to your headset. It's not the best solution, though, because music will still trickle out through the iPhone's built-in speaker.
iPhone software bug lets you stream music to Bluetooth headsets [Apple Insider]