There's no way to actively show how many people are in chat. At least not as it is right now. There's always a way. I'll see if I can figure it out. You can see who all is browsing the forums by looking at the very bottom of the page. What I've done in the past is just post a thread in the lounge saying "Chat is open" and hope some of the people join. But there has got to be an easier way. I'll put it on my to-do list.