The iPod, as a digital companion, has profoundly impacted millions of people in a very personal way. Its portability, by virtue of its small size and long battery life, meant that people took it with them wherever they went.

Our iPods could always be playing--on the bus, on the street, when working out, or while drifting to sleep--focusing our lives through a new musical lens. With the iPod guiding us through life experiences good and bad, each one of us becomes a star in our own private movie.

And private it is, encasing us in a secret musical bubble that tends to shut out others in public spaces, much to the chagrin of conservative cultural purists and gregarious subway-goers everywhere.

Within this bubble, many have enjoyed the primacy of their own music verses that would be imposed onto them by others. (Elevator music be damned.) The iPod's large capacity meant people could effectively program their own private radio stations with days' worth of content, which Apple's device could deliver in a novel play order called "shuffle."

That brings us to another point about listening habits inspired by the iPod: the diminishing form of the music album. Not only does the iPod have the potential to completely negate whatever playing order each album's creators intended, but its accompanying music store, which sells songs à la carte, delights in breaking up albums in ways never before seen.