There's a great website called onebag.com, with all sorts of tips on how to travel light. The section on traveling light with children is very short, though: it basically says it's impossible.
We agree; although Amy did a great job of marshalling all our belongings into a big suitcase, a small suitcase, a medium-sized diaper bag, a small toy bag, and a small snacks bag. No other check-ins or carry-ons, not even a purse.
Even better, she made sure that in the midst of packing as spartanly as possible, she didn't neglect fun for the kids. We're bracing for six hours on the plane and another three or more before or after, and Amy's well-prepared with toys, snacks, and other distractions to make an otherwise arduous journey somewhat fun for a three-year-old and a one-year-old. Gold star for Mama.