TexasCHLforum.com

With IRC you can setup an irc bot with chanop powers to kick/ban people who violate the language rules and that aspect of maintaining the channel becomes automated. In an extreme situation you can require that users get permission to speak from the chanop. here's a quick, off the top of my head, list of pros and cons for using an existing IRC network:

Pros:
None of your own bandwidth is used for the actual chat service.
Users can use their own IRC clients to connect.
Attract non-members who may become interested.
Most IRC networks have multiple linked servers so if one goes down users who are affected can simply reconnect to another server.
no need to maintain the network/server yourself.
IRC bots can kick and even ban users from the channel who violate language rules and perform other tasks.
Java chat clients are available that can allow users who want to connect but do not want to use their own software.
Chanops can lock the channel so that members must have a password to connect or lock it so that the channel is invite only.

Cons:
Attracts non-members who may be interested in causing trouble (that's part of online life and easily dealt with by using kick/bans).
Network and servers are not under your direct control.
IRC, like all chat options, has a bad reputation and can get nasty.
Statements that are made which violate the language rules will appear on screen until they scroll off or are closed out even after the user is kicked and/or banned from the channel.
Users can "PM" each other outside of your control thereby stalking/annoying/harassing each other.
Spam bots do happen, although established networks do work hard at identifying and banning such abusers.

Charles, Since you are considering a chat room may I make a suggestion? I would suggest registering a channel on an IRC network such as freenode and then setting up a java client on an html page here. This will avoid eating your bandwidth up, as well as keep upgrades to PHPbb simpler, and will allow people browsing the IRC server to find the channel and get interested in the site itself.