I never go anywhere without my phone, camera and money anyway but if I'm flying I'll take mp4 player & heaphones, 2 or 3 books, some music/nerdy magazines, notepad and pens/pencils, DS and gameboy and food.
And depending on the length/type of the flight, I'll either wear my contacts and take my glasses with me or wear my glasses (really long/overnight flights) and take a pair of contacts in a box.