By popular demand, I give you the shoutbox. It will appear on the upper-left corner of every page and updates itself every 10 seconds. If you'd rather it go away, you can hit the X in its corner and it won't pester you again untill you launch a new browser session.

Now, you can double-click the shout text to toggle scrolling

Clicking [<] will now open a shoutbox popup with a longer history and the names of those idling in the shoutbox. Those in italics are on a forum page, those not are on the popup.