Nice work! I was meaning to ask if you had considered using Ajax.

I was using Joomla/SMF before switching to vB, and used a really nice shoutbox as a module in Joomla.
That one used Ajax. It also had another feature which I would like to see you implement. Since I have your chatbox as a side module in vBadvanced, the space is limited. So I've removed the code that outputs the date before every message. In the Joomla shoutbox the nice thing was that if you held your mouse over the username of a person that had sent a message, it showed how long since that message was entered. Would be cool to have that here too.
Here's the previous version.