Uh, I'm "that guy."

Once we've hit the 10,000ft mark, the Bose go on my head and my MP3 player goes in my shirt pocket with the headset cord coiled behind it. Nothing hanging out that might get caught on something, and less convenient to remove and put back on again than simply leaving them on.

Besides, they're quite effective at canceling the sorts of noises I make in the bathroom. Unfortunately, I'm the only one that doesn't have to listen to them