With the news that American Airlines is now going to charge $15 for the first bag you check (which is actually not new, Spirit Airlines does it, as does RyanAir in Europe. The difference is that they are discount carriers), you might find traveling lighter useful. I highly recommend the One Bag website, which teaches you how to efficiently pack your bag, and recommends carry-on compatible travel packs. You also might find the One Bag, One World blog useful, as well as this handy comparison chart of travel packs. And don’t forget the packing cubes!