We've found a great way to tote carseats around in the airport (okay we're cheap and don't like paying for those airport cart things but we have 3 carseats we travel with). We slip a bungee cord in the pocket of each of our large suitcases. When we get to the airport, we take the carseats out of the car and use the bungee cords to fasten them to the suitcases. This way we can roll two things along together. We untie them during check-in, put the cords back in the pocket and they're there for when we pick up our bags again.
