It sounds like it might be advantageous to make the poster of the topic the admin for the thread. That way, each individual poster can control the conversation

It sounds like it might be advantageous to make the poster of the topic the admin for the thread. That way, each individual poster can control the conversation how he sees fit. Another idea that just came to mind from your "bike shedding" topic is the ability to move the entire thread of a side conversation into its own post and have each post link to each other. That way, you don't have to navigate through pages of side conversations you don't care about (like I do here on HN) and instead get a quick list of relevant conversations that the original post spawned. It also makes it easier to find certain conversations. I can't tell you how many times I've searched forums for a specific conversation and found it buried deep in a completely unrelated topic. Hiding arguments would have to be handled carefully, I think. Some people may derive value from watching two people argue about something. Sometimes, it's not just rhetoric and ad hominem, but actual information being communicated.