When I fly I usually pack several MP3 players but only one for the seat since is such a pain to dig around in those tiny seats. In the past I have used a simple soft case to hold the player and the Shure SE530s (Amazing isolation and sound quality for flying, ‘eff Bose!) all in one neat package. Though I did always worry about smashing it in between a seat or dropping it in the boarding and unboarding chaos.
So I stumbled on this little gem today at Best Buy. It’s made for the iPod (Ew, I know right?) but will work with anything that will fit. There is also a headphone cable leading from the inside to a plug on the outside for waterproof use.