Here's an interesting idea from the folks at Cupertino. Apple recently was awarded a patent for a device that would function as both a Bluetooth headset and a music player.
This is an interesting idea because the patent talks about the device functioning as a music player all on its own and not connecting to a device to stream the tunes.
Whether this ever sees the light of day is beyond me, but it's an interesting concept. It's basically a Bluetooth device for your phone communication, paired with an iPod Nano type built-in music player.
Definitely stay tuned on this one.