I'm updating the ipod with new music for the trip tomorrow... some Christmas music and a great band called Pink Martini. I can't imagine flying without the dumb thing now.
LOL... I don't even have an iPod yet. My never-travel-without item is my little DVD player and my Bose headphones. Even for a little flight like this one from SEA to SFO, I plug in a movie, slip on the headphones, and the flight goes by in no time at all.
For longer flights it *definitely* saved my sanity.
I can sleep on planes, but I usually don't.