Come Super Bowl Sunday, Amazon.com will get a leg up in the digital music race it's running against Apple Inc.'s iTunes Store. And not just any leg: Justin Timberlake's leg. The boy band heartthrob turned Grammy-winning R&B singer will appear in a spot for Pepsi, kicking off a yearlong $1 billion giveaway of MP3s, CDs, videos, consumer electronics and other items on Amazon. Working with Amazon this year is big deal for Pepsi, which said it will spend more on its "Pepsi Stuff" advertising campaign than on any past marketing effort. While the companies would not disclose financial terms of the deal, teaming up with Pepsi has the potential to transform Amazon from a niche seller to a major player. (AP)