I am The Compendium
Turnilk
What exactly does this meeting do in the story?If it happens during the story, then ask questions about it until you find your answer. Why are they in that place? Do they live there or are there on business or visiting someone or any other reason? Why would they start up a conversation with someone they don't know (if they don't know each other of course)? Are they going anywhere in particular? Do the characters have any goals that might bring them together in the same place and get them to work with one another? You get the idea I hope.
Well, this is sort of the problem. I know all those things, expect for if they have coinciding goals (other than just to talk). If they do, however, that's where I start questioning the plan. Is it too contrived or makes the world smaller by everyone knows everyone else? Or do I just need to keep an eye on continuity and remember that these guys met years ago?
So, you need them to start talking to one another, but can't figure out why they would do so? If that is the case, you could try having one ask another for directions (if they don't know one another). Its one way to start a conversation. Or as you mentioned earlier, a bar scene. Bumping into one another then having to work together immediately for some reason could work as well.
Having pretty much all the characters know one another right off is a little odd to me, but it can be used well enough. If you want them to not know the current events in each other's lives they could just be not close, or had a falling out, or just got busy and started ignoring some people in their lives (the last one happens to me all the time).
If there is a job to be done that both have to work on but don't tell each other about it, you could either have one or both be quiet about their work, or they could be under orders not to share any information with anyone else.
And personally, I'd always keep an eye on continuity. I dislike making mistakes, even minor ones, when it comes to the storyline and characters. Bad spelling and grammer don't bother me nearly as much.