Registration is not necessary to chat; you may simply enter a screenname and begin. In the event you leave or are disconnected, your screenname will be "held" for you for 15 minutes, but will then be up for grabs again.
However, if you would like to reserve your distinctive OO Forums username for all eternity, you may do so; please note that as of July 18, all past Chat Registrations have been wiped clean, and a new registration procedure put in place. When registering, please enter a valid e-mail address (you may keep it hidden from other users), and you will instantly receive a message with your username/password information. And this time, DON'T LOSE this information, otherwise you're going to make extra work for your Humble Webmaster. If you decide to register it's on YOUR head to remember your password, OK?
Whether you register or not: just get your name on in there and start chatting, Junior. Enjoy!