Here is a pillow that looks like the one that Ava has and likes for travel (you can borrow it for your next flight) -
http://www.bedbathandbeyond.com/product.asp?order_num=-1&SKU=14490698I use a small square pillow - but I should get a U-shaped one.
http://www.bedbathandbeyond.com/product.asp?order_num=-1&SKU=10060915In addition to the pillow, my red-eye flight regimen includes a Window seat, comfy socks (shed the shoes), eye mask from Brookstone, soft ear plugs, Tylenol PM. I put the ear plugs and mask on right after takeoff (after the cabin pressurizes), I usually sleep right up until landing.
To cut down on the pack volume of any pillow, I use a small SpaceBag to squeeze all of the air out -- helps fit it in my carry on bag.