I always carried an inflatable travel pillow with me when I was backpacking around the world and there are times I still use one on a stingy airline with no pillows. There are basic flaws in the two main types though: the basic pillow-shaped ones and the C-shaped ones that go around your neck. Neither is all that flexible in terms of how you can use it and where it will fit when you're in a cramped coach seat.
I've been testing this new TravelRest inflatable pillow from HiGear Design and as is often the case, a slight change in outlook has made a huge difference. By reimagining the shape and design of a travel pillow, this company has turned out something that looks strange but works really well.
Deflated, it rolls up into a small and light package about the size of a pair of tube socks. A snap keeps it from unraveling. You can even snap it to the outside of your carry-on bag for easy removal on the plane.
Once you're ready to use it, a few puffs into the valve gets it ready. What you're holding looks like an oversized quotation mark, one that can be used in several ways. The attached cinch line allows the TravelRest pillow to attach to the back of your seat and stay in place when your head starts lolling around. You can snap the bottom of it to your seatbelt to keep it more secure. If you're stuck in the airport, you can just sling it over your shoulder, hug it like a Teddy bear, and snooze for a while during your delay. (Don't be surprised if you start dreaming of your childhood bedroom...)
This pillow is also handy in the car. It can attach to the headrest and seatbelt for a nice nap during a long car ride---especially good for kids who have to be stuck in a car seat for hours on end. It's easy to wash after someone drools on it too.
The TravelRest pillow lists for $27 and you can buy it direct from their site or in some luggage stores.