In the four years since its introduction, the iPod has proven to be a versatile little device. Despite a relatively closed architecture, hackers have found their way in. Content creators and software makers put information at your fingertips when you're on the go. Would-be designers have added to the fashionable stylings of the now-ubiquitous white ear buds. Hardware makers and enthusiasts have augmented the iPod with new add-on gadgets. Here are a few dozen things you can do with your iPod besides listen to music.