I have an iPod but I seldom use it. It is because most of the time, I am in front of my laptop and playing music through the media player. Recently, we've been reading accounts of audiologists issuing a warning we’ve been told years ago - if we listen too loud for too long, we'll lose our hearing. When the Sony Walkman made its debut in 1979, audio researchers said the same thing. When the portable CD player hit the market five years later in 1984, the warnings were issued again. The difference? This time experts are pointing the finger to longer battery life and seemingly endless string of hits that can be played in our ears through the mp3’s, mp4’s and iPods without a break. There are many portable digital audio and video players on the market but clearly the Apple iPod is the market leader with 42 million units sold, 14 million just in the last quarter of 2005. Some iPods can play up to 20 hours straight before the battery needs recharging. Most units can ho...