If you already have a Jabber or Google Talk account, you can join the chat room 'osqa' on server 'talk.dzone.com'. There are usually people in the chat room, and you are welcome to stick around as long as you wish. Depending on how your browser is setup, you may be able to join the chat automatically by clicking on this link: <xmpp:email@example.com?join>
We also have recently opened a channel on IRC. It is just getting started, but you are welcome to jump in, chat and help get that moving, too!
Please note: people have had lots of problems trying to use the Google Talk web-based chat client for group chats. You're likely to get much better results with an application like pidgin, Trillian, or Adium than with the Google client.