I used to do it all the time on UAL out of SFO. Nice ride and never got less than business class. Just go to the international ticket counter and tell them you are wanting to jumpseat. They will probably print you a standby pass to go through security. Then just ask for the jumpseat at the gate and talk to the crew as you usually would.
If you travel in uniform in Asia, you are treated with respect as a pilot, as opposed to the U.S. I'd suggest doing so.