To answer the question in the original post without reading the whole thread...
I attend game days around DC when I can, either sharing the tricks I use in my homebrew game, or by donating DM duties to the Living series. When I travel I usually am looking for a game to hop in as a guest player, and now Wednesdays are an easy night to find a game at FLGS's no matter which city I visit. People pronounce kobold differently everywhere, but dice still roll the same, and fun is shared by all. Sometimes there are selfish players that want to 'win' by getting more stuff or rewards or whatever, or others that you might not like to game with again, but by being cool and having fun anyway can lead them to do the same - think Pay It Forward.
I keep a public ongoing wiki of our game sessions. Since the wiki tracks the number of unique visitors, it is easy to see that there are far more hits per day than we have players.
I also talk to others about the hobby to others, but not in a geeky check-out-my-half-orc kind of way. One or two sentences and that's it, then ask about their hobbies. If they aren't interested they'll talk about boating, skiing, baseball cards, or whatever, but those who are ask more.