LAUNCHED BACK IN 2001, Apple's iPod has arguably become the most iconic electronic device of the 21st century. With sales of over 100 million units, the iPod has dominated the market for portable audio—and now video—players. What's more, it's become a cultural phenomenon, and it may have ultimately saved Apple from the clutches of obscurity and irrelevance. That's not bad for an MP3 player that looks like it belongs in a dental office.

Of course, Apple's command of the portable audio market hasn't gone unchallenged. Just about everyone has taken a shot at the iPod, from consumer electronics heavyweights like Sony and Toshiba to PC alum like Creative and Dell. However, none have managed more than a shallow dent in Apple's grip on the hearts and minds of consumers.

During the iPod's ascension, Microsoft worked with various hardware partners on all sorts of would be iPod killers, with little success. Then Redmond took matters into its own hands, creating the Zune media player to directly challenge Apple's iMonopoly. On paper, the Zune looks like a competent challenger, too; it has a much larger screen than the iPod, integrated wireless capabilities, and support for subscription-based music services. But is it any better than Apple's status quo? I've spent three months with an iPod and a Zune to find out, and the answer might surprise you.