Cutting in line/jumping the queue annoys me to no end, so I will almost always say something (don't worry, I don't mind ). I will also let some of the hard-core cutters go, but making sure that they're wait in front of me is as embarassing as possible (hopefully to prevent them from doing it again).

That being said, I will "adapt" to the current situation. I was at SGN boarding an OZ flight, and some Korean businessmen decided to bypass the line of 100 that had already formed to enter the departure area (I was about 10 back, having waited for 45 minutes). Rather than speak out (because seriously, even the Vietnamese don't do that), I decided to take matters into my own hands, made my way forward, and blocked the cutters with an elbow and a hard stare. I guess they understood they weren't dealing with a "normal" pax, so they backed off.

When I got in, I exchanged comments with a SGN worker there, who rolled his eyes and smiled when I asked, "Is it always like this on OZ flights?"

Lesson: Stand up for yourself! And do it in a way that the others will understand.