: "They say talk is cheap. Google thinks it should be free. Google Talk enables you to call or send instant messages to your friends for free�anytime, anywhere in the world. Google Talk offers you:
Choice: Get in touch over email, IM or a call
Quality: Talk through your computer but hear your friends as if they were in the same room
Convenience: Your Gmail contacts are pre-loaded into Google Talk so inviting or talking to your friends is just a click away
Google Talk is in beta and requires a Gmail username and password.
Don't have Gmail? Get an account using your mobile phone (US only). "