I've been meaning to mention this. Recently, I had to travel to TX for a shoot. I didn't want to trust my audio gear to checked-in luggage. The problem was, my K-tek carbon fiber boom pole is way to long to fit in my standard carry-on bag.
As it turns out, k-tek makes an aluminum pole that collapses down to around 20 inches and fits perfectly in my suitcase. It opens to 6' 9" and they make both an internal cable and external cable version. You may find yourself in need of a boom longer than 6' 9", of course, but for the locked down shots and run and gun we were doing, it was fine.
We just did a cross country jaunt with full gear and the TSA only had problems with the "club like" items and they had to be stowed below. If they are really nice, you can hand it to the airplane's crew and they simply stow it below. Or, they just tell you to pack it below. I prefer to carry a "loaded" camera kit: camera, light, mic, batteries, tapes and an adapter that can be used with a dowel or whatever to make a makeshift tripod. I went to Iowa once to do a very important interview for a TV news type program and the airline delayed my baggage. Be able to work with whatever you have in your hands. Monopods can also take the place of a tripod in a desperate situation.