the ipad(get one with storage and a decent data plan) along with good old handbrake h.264 for movies and the kindle app(or apple's, whichever) are a fucking great way to kill time while staying low-profile.

yeah, a good case and then an otterbox-type one, one of the ten-dollar li-ion packs that will recharge the thing if need be, a stylus and dock, and a pair of closed headphones(noise-cancelling by definition sucks) like audio technica 50's or the venerable old studio monitor sony's and senn hd280's. just low-impedance shit that by virtue of being closed keep noise out, something like a grado 325i's great but doesn't shut outside noise out or keep your noise from emanating out. high-end earbuds are fine if you're into sealing shit into your ear canal perfectly then blasting down the thing until your hearing's a disaster. good for the money, there are full-sized low-impedance headphones for a little more of it that are comfortable or reproduce shit MUCH better than i can hear it.