But doubt you can do anything w/out replacing the metal completely. It looks like the metal is the same titanium Apple uses for the PowerBook G4 cases. (And I dinged that up the 2nd day I had it... of course not another scratch since -- but prepared me to guard my iPhone from the same fate)
Just consider it a little "personalization" on your iPhone.
Hey, it could be worse. At least it didn't sneak out and get a tattoo!
i'd say be VERY glad it wasn't your screen, just my $.02. trust me, a scratch on the back is livable after a week or so, but the glass screen cracking is worth no less than the estimated $275 it could take to 'repair' it...