what is the etiquette for if you are alone in the midst of a ready-established friend group

Also it was your friend's responsibility to introduce you and stuff, if that didn't happen it's no wonder you felt left out. Often people don't realise that someone doesn't know anyone - and they may not all have known each other either.

it is tough, though sometimes, going alone. that's why it's always worth bringing along a buddy.

i find the same thing works the other way: if i'm with a group of people i've never met before, i'll try to chat away and be pleasant/funny/not unnecessarily cuntish, and usually one or two people will be very receptive to that. whether or not the rest of the group follows suit doesn't really matter: if i've got a couple of people to chat to (and some beer to drink), i'm happy enough for the night.

anyway isn't the thing w.large-ish groups of ppl that they haven't ALL seen EVERY ONE of each other recently so spend a lot of time catchin up intro-group and cross-subgroup and everyone is assumin the unknown face is known to everyone but them

but yeah, the ppl who invited you shd at least introduce you to someone

Common logic says that the best thing to do is you should introduce the new friend round, and try to provide some entrance for them in terms of suggesting areas of commonality. BUT!!! I hate, hate, hate this - mainly because Joe used to try to do it, and was crap at it, i.e. he would either mangle it badly ("This is my partner Kate, she hates Sound Art" when introducing me to any other Sound Artist" or else big me up waaaaayyyy more than was reasonable, leaving me feeling very uncomfortable, i.e. "This is my partner Kate, she is a mathematician/artist/Proper Musician" which immediately provoked embarrassing questions where I had to reveal that I was just a housewife really. But that is an awful consequence of those being business socialising more than social.

I don't know; I hope that I have friends who are odd enough that they will flock naturally together. And usually I'm gratified enough that it happens when I introduce a new person into my fold. But whenever I go to someone else's do, I end up being the lone odd person. Argh.

oh, but the inherent comedy value of that ... especially if you're unlikely to ever see these people again ...

well if you have something interesting to say about it then yeah (e.g. if you have a kid who is being a slut or something). if you aren't interested in their kid stories how you do expect them to be interested in you?

Mostly, though, it seems like people our age (by this, I mean late-20s, early-30s) have been around enough to be in a similar position.

I encountered this fairly recently at a birthday party where I only knew (and just barely) the hosts. I was sitting at a table eating snacks with three of the party-goers when suddenly they say to each other, "Ooh! Let's all go in the other room together!" so then that just leaves me at the table eating chips. It was pretty upsetting and rude, but at the same time I realized that they grew up here and have known each other for years and years and they probably didn't think anything of it.

It works about 50/50.