How about a Bluetooth inside?

Daisy multimedia had a MP3 player with bluetooth.
specs:
256MB MP3 player, weighs: 25 grams, have the ability to add extra memory like SD card, support for AAC audio files with FM tuner, a built-in microphone, integrated Bluetooth for using it with a cellphone as a hands-free headset, (it doesn't look like it uses Bluetooth for file transfer).