o My idea for conversations is that if you reply to a message you now have a two-message conversation: which illustrates the rule that a conversation is a set of messages linked in a tree-shaped structure, linked from child to parent by virtue of the child being a reply to the parent.

o Within any conversation tree there will thus be parents, children and siblings, and users might want to see any/all of those in "viewing" a conversation.

o I could see one view of a conversation that is simple a forward-chronological listing (a stream) of the messages in the conversation.

o But I could also image users wanting to navigate the tree to follow the threads of discourse; which means a different UI than just a list of messages. Perhaps, then, we'd have to open conversations into their own windows to view them...