Run /Applications/Utilities/Disc Utility and see if it appears? Does the 'Mount' button light up or not?
It's probably formatted for PC's with Creative's version of the iTunes software on it I guess ? If you wipe the drive by Formatting you could then write files to it,
but you'd have no software on there to play them with ...
i.e. bottom line is it's not compatible with iTunes/Mac OS if there's nothing on their web site to support this and you can't mount the drive.
Addendum:
Check this out
http://www.wentnet.com/projects/xnjb/
"XNJB is a Cocoa graphical user interface for Mac OS X for the Creative Nomad range of portable MP3 players and newer MTP players."
