books, books, books..... my girls (flew with them at 9mon, 2 1/2 yrs, 4yrs. were most content when we gave them our undivided attention. Color with them, stickers with them, books with them..... We did have something cool for our last night trip. A battery operated lite brite. We also fly early in the morning and late at night, lots of the trip is taken up with eating breakfast (I pack) or dinner (again packed) plus we let them go in their jammies (5am is too early to get dressed anyway!) and change on the plane. Fill that time, fill that time....