There are chat rooms in every group. Most are under used. Go to the groups tab and search for chat. there are several 24 hour chat groups and in Newcomers club the chat is always running. You do have be a member of the group in order to chat, but any member can open it so if you know your friends are around you can chat with them.
Also in the group tab (or any group page) there is a blue box in the upper right hand corner. Under the explore groups link you will see active chats. That will tell you which groups currently have rooms open.
at 6:31 PM on Jul. 31, 2010