At your request, we've implemented a chat log which records all of the public chat in a room. If you miss a comment from your friend, you can now scroll through the log to see what they've said. You can open the log at any time by clicking on the chat log icon in the nav bar.
To make it easier to tell people apart when chatting, we've color coded the user names that appear in the chat dialog box, so you can easily tell if the person chatting is a friend or not.