I've travelled extensively worldwide, as well as played with other men around the world.
I think I have quick and accurate Gaydar among men of my own culture - Americans. The secret for me is in the eyes, how long do they hold contact & connection to you. And, of course you can always watch where those eyes go when they're looking at someone else (or you). Gay men are also less frightened or feel more comfortable being closer to another man physically. It is sometimes amusing to see how frightened straight Americans are about touching another man inadvertantly or being grazed by another man.
But these clues seem to be less helpful with men of different cultures- particularly Brits and Europeans. European men seem to be more comfortable holding another man's eye contact regardless of their orientation. And their field of 'private space' seems to be reduced and they are less concerned about another man's contact or nearness. You have to rely more on watching their eyes watch what body parts of others. In contrast, Japanese men of both orientation seem to be more shy about holding eye contact for more than just what's required to aknowledge another man's presence. Like Europeans, their zone of privacy is reduced so an occassional touch or graze is quite matter-of-fact. But gay Japanese men DO cruise other men (where the other man isn't looking) with abandon. So I still say, focus on the eyes.
There's a few parts of the world I am less experienced with: Indonesia, Northern Africa, Middle East and the subcontinent of Asia.
