
And you can invite new users to sign up for Gmail and Google Talk. You can, however, talk to any other Google Talk user, or any other person who's using Google's Gmail service. None of these IM networks are interchangeable none of them interface with each other.

If your friends are all using AIM or MSN Messenger, you can't talk to them with Google Talk. You see, Google Talk only lets you instant message with other Google Talk subscribers. Here's where there's a bit of a speed bump. Once you have Google Talk installed, you need to find someone to talk to. Learn more about signing up for Gmail in Chapter 21, "Sending and Receiving Email with Gmail."

To use Google Talk or Google Chat, you must have a Gmail username and password.
