To initiate a conversation, you can either select someone from that recents list or--if the person you want to chat with isn't there--type the person's name or phone number in the To: field at the top of the right-hand pane. You can remove someone from the conversation list by hovering your mouse cursor over his or her entry, then clicking on the little X that then appears.

The right-hand chat area isn't dramatically different from one of iChat's conversation windows: There's a text-entry box at the bottom where you type what you want to say; until you begin typing, it displays the name of the service you're using for a particular chat. At the top, there's a camera button that gives you quick access to video chat--more on that in an bit. And in the main window is a transcript of your previous conversations.

If you really miss the old iChat interface, don't worry: You can hit Command-1 (or select Window -> Buddies) and you'll see a buddy list like iChat's. From there, if you double-click on a contact, you'll be taken back to that right-hand conversation pane, ready to chat with that person.

As in iChat, you can do group chats in Messages, but the process is slightly different: In iChat, you could select multiple people in your contacts list for a chat. You can do it that way in Messages, too, using that Buddies list. Or you can do it in the primary chat window, by entering multiple names, numbers, and email addresses in the To field. When one person replies, everyone else sees that response.

If, on the other hand, you're having multiple one-one-one conversations at the same time, you can open individual windows for each one by double-clicking on each contact in the left-hand contacts list. That may be easier to manage than juggling a bunch of conversations in a single pane.