Sign up for an instant messenger account with AOL Instant Messenger or Google Talk, or sign up for a MobileMe account if you don't have one.
Launch iChat.
Set your status to "Available" if you haven't already.
Open up your Buddy List. Go to the top menu, select "Window" and click on the name of the Buddy List you want to open. For example, if you're using AIM, click on "AIM Buddy List" to open up that account's Buddy List.
Find a friend you want to chat with and click on her or his name. Make sure that friend has an audio or video icon next to their name in the iChat Buddy List.
At the bottom of the Buddy List window, click the Audio Chat button (the one that looks like a telephone). The chat will begin when your friend accepts your Audio Chat request.
Select "Record Chat" from the "Video" menu at the top of the screen. Recording will begin when your friend has given permission to record the audio chat. You'll see a red light next to the mute button (a microphone with a slash through it) while the conversation is being recorded.
Select "Stop Recording" from the "Video" menu at the top to stop the recording.
Navigate to Documents/iChat/iChats to find the audio chat file that was saved for you. Double-click it to add this iChat conversation to your iTunes Library. You can then sync it to your iPod or iPhone if you want.
Open the iChat program and log in to your AIM or other messaging account.
Go to "iChat" in the top menu bar and select "Preferences."
Navigate to the "Messages" tab of the preferences window.
Check the box next to "Collect chats in a single window."
Close out of the preferences window and start a conversation with someone on your buddy list. Then start a second chat, and the windows will combine, with each conversation getting its own tab in the messaging window.
Go to "View" in the top menu bar, then click on "Messages" and select from Balloons, Boxes, Compact or Text. This allows you to customize the look of your tabbed chats.
Click the plus sign in the lower left corner of the main iChat buddy-list window.
Select "Edit Groups" from the drop-down menu that appears. A pop-up window will open that lists all current groups.
Click on the name of the group you wish to delete, then click the minus sign at the bottom of the pop-up window. The designated group will be removed from the list.
Click the "OK" button at the bottom of the window to save the changes and permanently delete the group.
Open the iChat program by clicking on the icon in the dock.
Click the plus sign in the lower-left corner of the main "Buddy List" window.
Select "Add Group" from the drop-down menu.
Enter a name for the new group you wish to create in the pop-up window. Click "Add" when you are satisfied, and the new group will appear in your Buddy List.
Drag and drop contacts from your Buddy List into your newly created group's title to assign them to the new group
Open iChat on your computer. Click “iChat,” and select “Preferences” from the drop-down menu.
Click the “Accounts” tab in the Preferences window.
Click the “+” sign at the bottom left corner of the Preferences window. A pop-up box appears.
Click the down arrow on the drop-down menu next to Account Type. Click “Jabber Account” from the menu that appears.
Type your Gmail address into the Jabber ID text field. If you have a Google Talk username but no Gmail address, type your username followed by “@gmail.com.” For example, “yourusername@gmail.com.”
Enter your Gmail or Google Talk password into the Password text field.
Type “talk.google.com” into the Server text field. Click “Add.”
Click the Google account you created from the Accounts box in the Preferences window. Select “Server Settings” from the main portion of the window.
Type “talk.google.com” into the Server text field and “5223” into the Port text field.
Check the boxes next to “Connect Using SSL” and “Allow Self-signed Certificates.” You don't need to check the box next to “Warn Before Password is Sent Insecurely.”
Type “iChat” into the Location text field. You are now able to see your Gmail and/or Google Talk contacts in your iChat Buddy List.