There are a few MP3 players in the thumb-drive form-factor out already, but very few of them have an LCD screen with a built in microphone. This Sweex Blue Bay (I typed "Blu" seven times out of Blu-ray muscle memory) has 256MB, 512MB, 1GB or 2GB of storage with MP3 and WMA support. You can use this as a standard thumb-drive for storing documents and bust out the tunes when you're commuting between community college and your parents' house.
Product Page [Sweex]
Sweex Blue Bay MP3 Player [Tech Digest]