Showoff! :P
I bought a case, but it ruins the whole "Im an iPod Touch, sleek, chique, sexy and easy to use!" So I just let the back get scratched without a case. Get an invisible sheild for the screen but if your not bothered about the back then you may aswell leave it.
I got a case for my old iPod Nano, even with the case, dirt got into the case and scratched it anyway, maybe not as much but still scratched it.

