wot-Mike,
I just wanted to say Thank you on behalf of us here at RaiderSoft. Your script is great!! Please e-mail us the next version so we can put it on on our site as well if you wouldn't mind.
Also, I wanted to let everyone know that we've just completed a script that will allow you to authenticate access to your chat room via your vBulletin database. You'll need the Platinum level service, and this script:
http://www.sigmachat.com/panel/extras/auth_vb230.zip
Once you have it installed, users who belong to groups with posting privileges will be allowed in the chat, and users who belong to groups with moderating privileges will be admin's within the chat room.
We've also developed a real-time Who's Online module that could be incorporated into vBulletin with a little work. The module is still fairly expensive (1/10th of a cent per hit) but should ease up soon.