Speakers! Yes. Not only is it good for us peripatetic types on airplanes, but our car has an input plug, so plug in the iPod and tunes play on the car speakers. So good for driving between Las Vegas and Los Angeles (have done it twice in the last month). You can even arrange Road Trip playlists.
Not to mention that I had to collect and burn 2 hours of music for the Hugo Awards ceremony. If I had just showed up with CDs, the tech crew would have laughed at me. Instead they loved my CD with MP3s and printed playlist. (Disclaimer: LAconIV had a blank ASCAP/BMI license, so we were licensed to play these tunes in a public venue.)
Words that LJ spellcheck do not know: iPod, playlist/s