Watch your back, iTunes: Amazon's now in the game of selling digital music to iOS users. The retail giant has optimized its store to let owners of iPhones and iPod touches browse and purchase from its 22-million song catalog.
To sidestep Apple's rules about taking 30 percent of purchases, though, Amazon's store isn't available via a native app, but rather in a Web interface that iOS users can access via Safari atwww.amazon.com/mp3....