Pack things in your carry-on that you can do in the airport and on the plane. Bring a novel or two. Pack puzzle books, such as crosswords or Sudoku, and carry a pen or pencil to work them. Include coloring books and crayons for your children.
Listen to music. An MP3 or a CD player fits in your carry-on bag easily.
Eat. If you are going to be there for a long layover, take advantage of the airport restaurants.
Entertain your children. Some airports have play areas with arcades and other entertainment.
Bring a portable DVD player so you or your children can watch a movie. Computers and cell phones are not always an option in an airport since you may not be able to get service, but watching a movie is an option. Bring games to play on a Game Boy or a similar device.
