I have a Zen class bag (by Nirvana). Here’s the Amazon page for it. On an airplane trip, the bag hooks over the folding-down tray on the seat in front of you, and its many pockets place a remarkable number of items at your finger-tips. (On the trip home, there was no seat right in front of me. Instead, I hooked the bag over my TV monitor, and that worked just as well.)
I usually try to put everything I might need in the Zen Class bag: magazine, book, deck of cards, earplanes, medicines, vitamins, pen, etc., etc. And I was lucky. On the plane trip out, as we were walking down the corridor to the actual plane door, we encountered a dragonlady who forced almost everyone, at this last moment, to check their carryon bag.
“Just let me take one thing on the plane,” I said. I took the Zen bag out of my rolling case, and also took out my iPad 2. I slipped the iPad into the Zen bag, and that was all I took on the plane. And for an 11 hour trip, it was more than enough.