I have a Pelican 1510. Supposedly the largest legal size for carry on. Doesn't hold as much as I'd hoped with the padding configuration, so it's usually just my overflow case. Also have a Think Tank Urban Disguise 60. The Think Tank holds an amazing amount of gear and looks like a simple brief case. It won't work for super-tele's but it will hold a bunch of everything else. I could probably carry both on to the plane, one as a personal item and the other as the carry one, but I've never tried. I like John's concept though, might have to adopt that idea and toss the Urban Disguise inside the Pelican and get rid of the padding.