I don't have one but I thought this was a good idea before they even invented it:

Lexar MPC-231 JumpGear MP3 Digital Music Player for JumpDrive Sport

http://www.amazon.com/exec/obidos/tg...&s=electronics

You buy usb flash drives in any capacity and plug them into the music player.

$36 for the player
$30 for a 256 MB flash drive
$50 for a 512 MB flash drive