[CentOS] share folder as USB mass storage device

Hi all!

Maybe I'm just being silly here, but I'm wondering if anybody has ever
used their computer for sharing files over USB. That is, the computer
pretends to be a USB mass storage device.

This could be useful for connecting to media players and such that
support you plugging a USB harddrive or memory stick.

Surely, somebody must have thought of this before :-D

regards,
  Bent