Im considering taking a flight in a couple of months and Im curious about traveling with an infant/toddler. My daughter is currently 14 months old. When you have a child of that age do you buy an additional ticket/seat, or do you just hold the child in your lap? Any advice on keeping them calm during a flight? I know that I have seen children get upset when the pressure changes on a plane, etc. Also, do most people take their car seat along or are they readily available at the destination car rental agency?