You got your MP3 player in my sunglasses! I got my watch in your MP3 player!
The best thing about these is that they don't hold much music (between 128 MB and 1 GB). You'll be less heartbroken when you leave them on the table at a restaurant and never see them again.
They also make watches with retractable USB plugs, earphone ports and player controls built into the watch face, which is kind of neat. The watches look a little less dorky than the shades.
They're from Xonix Electronics.