A new invention is a B-Tourist strip, as it's called (for the economy-class masses). It's an elastic seat attachment that functions like a hammock for your head and neck. You can easily pack one in your carry-on, and attach it to the seat in front of you after take-off and the other end wraps around your headrest, creating a dual privacy screen and headrest. Maybe for the passenger in a window seat, as I cannot imagine having this contraption in a middle or aisle seat.
Also, I believe the FAA would have issues with this device since it would impede progress to an emergency exit, during an evacuation. So, while I applaud the attempt to make economy travel a little more bearable, this device (in my opinion) simply will not fly.