A few days ago I shared my ten tips to surviving traveling with children. I listed Lego, sketchbook, puzzle, and Play-Doh among others but one thing that really changed the way we travel by plane is JetKids by Stokke BedBox.
It is spacious, multipurpose luggage that your child can sit on or be pulled on it. You can easily store toys inside, and it comes with a little mattress that will turn the plane seat into a bed or longer place (if your child prefers to sit).