As of this morning, I had reached a point of stoic reserve about covering the whole ditching your MP3 player issue, a topic that I've been avoiding like the plague since it makes me depressed and nostalgic. Happily, I was saved at the last minute by an article about increased hearing loss in adolescents that the Journal of the American Medical Association (JAMA) posted yesterday.
As more and more people listen to music on the go, whether through their cell phones or dedicated MP3 players, innumerable ears are exposed an assault of audio through headphones. These listening implements aren't inherently bad, but they can contribute to hearing issues over time if certain precautions aren't taken. The following advice can help to ensure that you continue to hear all sound as nature intended it.
I feel that this should be an obvious point, but it always bears repeating: DON'T listen to your music at ear-splitting levels. The quickest and easiest way to damage your hearing is to expose your ears to overly-loud sounds, music or otherwise; this is the reason that people who work at factories (and some other loud locations) are often required to wear earplugs under local health and safety laws.
So how loud is too loud? Anything over 75 decibels, according to one study. Of course, it's tough for most consumers to accurately measure this; when in doubt, DO employ the volume limiting feature on your listening device. Apple's various iPods and most of Sony's Walkman players include this functionality. Alternatively, you can even pick up a pair of earbuds that ensure safe listening levels, such as the Ultimate Ears Loud Enough earphones.
Beyond that, DO purchase sound-isolating earbuds or noise-canceling headphones, especially if you constantly find yourself listening to your portable player in noisy locations, such as on public transportation or on an airplane. The benefit here is that either of those features helps to block out ambient noise, which then reduces the need for you to turn up your music to overcome that noise.
And this is a bit off the topic of portable device listening, but DON'T overlook the other situations in which you put your hearing at risk, concerts being the most obvious example for any music lover. Although the sound is not being piped directly into your ear (already a plus), it is exceptionally loud. You should always wear earplugs at live shows. If the standard foam variety bastardizes the sound too much for your tastes, DO invest in a pair with audio filters, such as the Ultimate Ears Custom Earplugs or the more affordable ER-20s.
Finally, if safe listening--whether for yourself or your loved ones--is a major concern for you, DO educate yourself as much as possible. This article provides some extremely detailed and useful information on hearing loss, including this most important fact: it's permanent.