Shoutbox

If one person in that chat had the plugin to relay the data to the other client (like a quote every time a new message is sent) then yes it could work. However this just seems stupid and you may when you are "listening" intervene by telling people what to say when they don't want you to know. Where with a chat log you have no influence over the conversation you can now stir things up. I do not like\see a need for this plugin unless you are extremely unpopular...