Click Add Friend
Launch Google Talk by double-clicking the icon and signing in. To add a friend to your Google Talk contact list, click the Add friend link at the bottom of the Google Talk screen.
Invite a Friend
After you click the Add friend link, you are brought to a screen that asks if you want to invite a friend to Google Talk. This is a slightly confusing screen because it implies that all you're doing is inviting them to download and install the Google Talk software. In fact, though, you're adding the person to your list of Google Talk friends in your contact list.
To add someone, type his email address into the Add box, and click Next. If you want to invite someone from your list of Gmail contacts, click the Choose from my contacts button. From the screen that appears, enable the check boxes next to the people you want to invite to join you on Google Talk, and click OK.
To complete the procedure for adding a friend to your contact listand inviting him to download and install the Google Talk software so he can exchange instant messages with youclick the Finish button.
Check Your Friend's Status
At first, your friend shows up on your contact list (the list in the main Google Talk screen), but with the word invited after his name. If he has not yet downloaded and installed Google Talk, the invited status stays there. After he installs Google Talk and registers it, the invited status disappears and he is permanently added to your contact list.
Similarly, if you've invited someone who already has a Google Talk account, the invited status disappears after a time.
The various instant messaging clients, such as Google Talk, Yahoo! Messenger, MSN Messenger, and AOL Instant Messenger (AIM), do not speak to one another. So if you're a Google Talk user, you can't, for example, send an instant message to someone who uses Yahoo! Messenger. As of this writing, however, Google and America Online have announced that they will cooperate to enable users of Google Talk and AIM to send messages to one another.
Manage Your Friend List
When you've put friends on your contact list, you can manage how to display the list, and you can take action on the friends listed in it. Right-click a friend on the contact list to display a context menu of options. You have the following choices:
Rename You can rename the friend's entry in your contact list. For example, if the friend's name appears in your contact list as a nickname that is hard to decipher (such as Joe43XC3), you can rename the entry so it appears as his real name. Or if the entry appears as your friend's real name, you can rename the entry to display a nickname or something descriptive.
Remove If you no longer want the person listed in your contact list, select this option to remove the entry.
Block If you don't want to receive messages from the person or allow Google Talk to let this person know when you're online, select this option to block him.
If you've sent a contact an invitation and he has yet to respond to you, two additional options show up on this screen: Invite Again and Withdraw Invitation. Those options do exactly what they saythey enable you to send another invitation or to withdraw the one you've already sent.
Sort friends by name This option arranges the entries in your contact list in alphabetical order, rather than in the order in which you added them to your list.
Hide offline friends This option hides the names of people in your contact list who are not currently online. This option is useful if you have a long list of friends. If you hide offline friends, it is easy for you to see at a glance who is online and determine with whom you can communicate.
Also show Gmail contacts You can display the names of all the people in your Gmail contact list. For any contacts who are not also on your Google Talk friends list, highlight the name, click the Invite button that appears, and go through the process described in steps 24.
You can have your entire Gmail contact list automatically show up on your Google Talk friends list. To do that, at the bottom of the Google Talk screen, click the Show all xxx link, where xxx is the total number of your Gmail contacts.