Pretty much all of my friends with whom I have regular contact are aware of my homoness. For many of them, I'm their first really personal contact with anyone with same-sex attraction who isn't a clownishly gay coworker or whatnot, so their learning curve has been steep.
As their first "token gay friend", I have proud little trainer moments when they use a term like "family," "moho," or "twink" casually in conversation as if everyone should know what this word means. OK, actually that's not entirely true: I still feel a bit awkward when my straight friends refer to someone as a "twink". I don't like that word and don't remember teaching anyone what it means, but one or two of my straight friends have used it, to my mild chagrin. It does, however, indicate a certain level of comfort with the topic that is oddly comforting even if simultaneously disconcerting. But I'm digressing: some of the proudest moments are when they successfully identify a gay dude in a crowd or come back from church saying, "Yeah, I'm pretty sure there are a couple of gay dudes in my new ward. You need to come verify them for me." And when they've asked me to offer my opinion, to throw my gaydar readings in the mix, mine often agrees with theirs.
But they're not quite fine-tuned yet. They catch the obvious ones, or the ones who are more "out" or flamboyant. And sometimes, they even catch the subtler guys by a hand movement or the way they talk about wanting a family but never mention looking forward to having a wife...but they're still thrown off by some of the finer points or confounding variables involved when it's a closeted moho who may or may not even have admitted his own mohoness to himself.
For example, I'll meet a guy and get an immediate vibe and suggest we might have "family" here, and they'll say something like, "No, he's definitely not gay. He talks about girls all the time," or "Oh no, he dates girls," or, "He made out with my roommate and I know for a fact he liked it." My response is usually something like a yawn or a slight eye roll, followed by, "Well, he may not be, but I'm sayin' I got blips on my 'dar, that's all." Or I might sometimes challenge them: "OK, so he talks about girls all the time, but has he dated them?" Or, "so he dates girls, but how many girlfriends has he had?" Or, "Listen, I can't tell you how many gay guys I've known who have enjoyed making out with girls here and there but who still prefer making out with guys and who don't fall for girls like they fall for guys..." I'm not trying to be contrary or make the whole world gay. Sometimes, a guy sends signals that confuse my 'dar, and the blip turns out to be nothing, so I have to acknowledge that probability too. I merely try to indicate to people that making out with or being married to a girl is not a sure sign of straightness.
There's a lot told by eye contact, and maybe this is something SSA/gay guys are uniquely equipped to pick up on because we've been there, done that and because there's something that happens between two guys attracted to guys, a sort of subtle, "Are you family? I think you might be family" exchange that happens in an instant, or a lingering eye contact that may either be mildly flirty or "oh no, I've been found out"-y. I'm not sure it can be taught, but I intend to try. Of course, I can't mentor my young 'dar apprentices in the finer points of homo-location until they learn that "made out with a girl" does not equate with "no chance he's gay", so we're taking baby steps, here...