This keychain-borne iPod Shuffle case, called “The Bevy” includes an integrated bottle open positioned just over the hole for the controls. You might thing it likely to scuff up your Shuffle just looking at it, but the Bevy doesn’t actually work until you remove the iPod first. You can wind your headphones around the outside when they’re not in use.
The only problem seems to be that it’s not actually on sale yet.
Update: Reader “Anonymous” points out the Bevy is also available on Amazon. And he or she is correct! (It’s $15.)