When you have hours to kill between flights and are in a foreign country airport, there are an increasing amount of tours and activities to occupy your mind (and your kids, if you're a parent). Read full story at New York Times.
Amsterdam has a 4-hour tour of a clog factory with a canal ride that you and the kiddies can take for a couple hundred dollars, for instance. Great way to get a peek at a place you're just passing through but is a detour from your itinerary.
I once took the train into London and spent a day shopping and walking through cobblestone streets in between Washington, DC and Tel Aviv, Israel. It was a great way to pass the time and helped me stretch my legs. Good to know tours and activities are out there though.