[CentOS] Reverse engineering USB devices

I'm pretty sure this is the wrong list, but maybe some clever people
here can redirect me...

I have a "RCA RS2100 Bookshelf Audio System"
  http://www.woot.com/blog/viewentry.aspx?id=2744
This is radio/CD/mp3 player... PLUS it can stream audio wirelessly.
You plug a USB device into your PC and you can remote control what gets
played from the RS2100 remote control ("Wireless Musiclink").

BUT only with Windows Media Center.

When I plugged the device in it appears to look like 3 devices; a HID,
an audio device and something else I can't remember (I'm not at that
machine at the moment).  My feeling is that the HID is used to inject
commands from the RS2100 (eg "play track <x>"), the audio device is for
streaming and the third device is feedback for the remote display.

The question I have... how can I reverse engineer the protocol used so
that I can make this work on my CentOS machine?  (I don't want to run
a Windows instance just for remote audio!).  Any hints, tips, pointers etc
much appreciated.

Thanks!

-- 

rgds
Stephen