There was something in Pop Photo a couple months back about the restrictions involved in taking tripods and monopods aboard commercial aircraft. Apparently, the official policy (in the US at least) is that pods made of carbon, or anything non-metallic, are ok. Metal ones are harder to screen for weapons via X-ray, and are therefore still prohibited. Now whether or not the local security guys at any given airport understand that policy completely may be an open question.
You don't appear to have any lens that goes very wide. I think I'd want something much wider for interiors and such. Why not go buy a new 18-55 EF-s IS? It goes much wider than the 24-105, is very sharp even wide open, and is extremely inexpensive. Being so much smaller than your good lenses, it would be far easier to conceal, and would draw a lot less attention. IS couldn't hurt either. And if it didn't work out, you won't have wasted very much money.
My mother ended up with my 20D and some of my older lenses. She just got back from a similar trip to Laos, where she was doing reconstructive surgery. I told her to take whatever lenses she wanted, but to just leave the 18-55 on as much as possible. I figured the last thing she needed in those conditions was a sensor full of dust, and the 18-55 covered a lot of the work she needed to do, especially with patients. She was also worried about theft, and an old 20D with an 18-55 would be a lot easier to replace than any L lens. Apparently, that strategy worked pretty well for her, and she only needed to get out the big glass a couple of times.
