Say you've succumbed to the omnipresent Apple advertising on the El (or, perhaps more likely, you didn't need any convincing), and you, like everyone else on the Belmont platform, have that personal audio device known as the iPod. You know it can play more than music, but how often do you refer to its built-in address book? Well, assuming you've got one of the new-fangled variety that has a color display, iPod Subway Maps provides a functionality you might actually use. Install the site's CTA maps on your 'Pod and never forget which direction the Purple Line runs through the Loop again.