I just traveled on my own with our Britax (and a three year old) this weekend. Our favorite travel item is the GoGo Babyz cart! It is simply a base with wheels that you attach the car seat to. Only takes one strap through the bottom and voila! wheels and a handle to push it around with. Makes airports a breeze. I use it to hold our other bags so I have hands free, or I can even put my son in it and use it as a stroller in the airport. And he loves to push/pull it around so he becomes helpful, too.
Then, I wheel the entire thing to the jetway (gate check it, don't bag check it! it's free, less risk for damage and there as soon as you get off the plane) and after our flight, pick it up at the jetway again and wheel it out. Just tell the gate counter that you need a tag to gate check it and they give you one with no hassle.
When I get to our car, I just unstrap it in a few seconds and it's good as new.
Love, love, love this thing.
We bought ours online from One Step Ahead.
(oh, the one thing "wrong" with it is that you have to take the car seat off the base to put it through security. not a big deal, but does add a few minutes to the line to get it off and then on again when you are done.)