Last night, I figured out how to listen to any song, either via iPod app, radio apps, Safari, and any other app from the earpiece. Just open up your favorite song, then open Shazam Encore*. You can leave Shazam and return to the home menu, and the music will still be playing from the earpiece. And surprisingly, the quality is superb! From iPod app / Radio app: just choose a song, open Shazam, and done. From Safari: Open up any video/song (even if it's from YouTube), load it up, and press home. Open the multitask bar, press play, then open Shazam. To stop playing from the earpiece, just delete Shazam from the multitask bar. *I used Shazam Encore (the paid version), so the lite version may differ. Only works with iPhone 4 and iPhone 3GS with iOS4. Enjoy!