I've noticed that most Lismore RPers tend to adhere to a pretty strict posting order even in casual scenes. It can certainly help keep things orderly; that said, I've noticed that when scenes start to get up to five or six people, you end up waiting 30-60 minutes between posts (depending on how many people say "oops, didn't realize it was my turn" per round), and end up having to write posts like:
Ninjadude nods to Smackypants and says "Yeah, I see where you're coming from." He waves at the new person arriving on the scene, and then looks curiously at the quiet girl who finally piped up into the conversation. "That's an interesting accent you have there." Ninja frowns at Pirate after Pirate mentions piracy, and says "You'd best not try that around here, or I will stab you in the back." He smiles when Ninjadudette shows off her new sword, reaching out for it with a quiet, "Mind if I have a look? I hope it was everything you wanted? Oh, and hello Fellaguy. Everything going well with your whatsits?"
I realize my bias is already showing, but honestly Lismore is the first place I've been that does this, even when there's no action going on. Most places, people are free to post whatever whenever, and have the courtesy to hold off if something they do or say is particularly important, or really needs a response. Carrying on half a conversation while trying to pin someone to a wall, for example, is kind of silly.
To be fair, I've seen it go the other way - I used to be on a MU* where there was one fellow who could type crazy WPM and would pose between every single pose of every single character. That got old too, and if I see that happening here, I will probably gently nudge them in an IM and suggest they slow down a bit.
Long story short, I'm curious what others think, but for me, I'm going to start posing at what I think is a fair speed based on the conversations and people involved. Folks are free to ask that I wait from time to time, or slow down. Feedback is fine. What's been happening though is I'm starting to try and avoid scenes with more than two or three people, and that's a bad mental association to draw. I want to be happy there are people around and there's activity happening, not have an urge to detach and log off because unwritten scene etiquette is frustrating the bejeezus out of me.