Breakaway offers a little feature that you won't find in iTunes: it will automatically pause the media player when the jack of your haedphone is plugged out.
This will prevent you from embarassing situations, especially if your music is on really loud.
Breakaway only takes a few seconds to set up.
Make sure you check 'headphones mode' to make it work and 'resume play on reinsert' to automatically restart your music once you plug your headphones back in.
You can also set a mute key and have it force open iTunes.
Breakaway is what we like to call a niche application. It those one specific thing, but does it well.
If you find yourself listening to your music with your headphones most of the time and don't want to find yourself in the unpleasant situation of having it blaring out of your Mac when you remove your headphones then this is for you.