Mp3 players are everywhere. You can hardly turn the corner without seeing someone-whether it is a child or a teenager, and adult or a senior citizen-listening to an mp3 player of some sort. The mp3 players themselves have become quite advanced-not only can they hold many songs (some of them as much as 20,000), but many of them can hold photos, play videos and T.V. shows, and play games as well. There are even mp3 players especially designed for children that include parental controls. But it...