Despite its runaway popularity, the Apple iPod suffers from the same problem that afflicts nearly all other portable MP3 players: the included earbud headphones are subpar. That's created a market for replacement iPod 'phones that offer better sound quality and a more comfortable fit. We've put together a list of some of the best iPod replacement headphones available. Of course, they'll work just as well with any other portable device--if you don't mind the "iPod white" coloring.