Earlier today we told you about Google planning to offer phone calls through Google Talk in Gmail and now Google has officially announced that users will Gmail. As I had said, this feature is tightly integrated with Google Voice and is offering free phone calls in U.S and Canada, at least till the rest of the year.

Calling rates to several countries are pretty low, for example calling India using Gmail would cost you 6 cents per minute to both landlines and mobile phones, calling to UK is about 2cents. This is on par or a bit higher than several calling cards available in the United States. You will find all the calling rates at this page.

Google will use your Google Voice account number as the outbound caller ID. You can also receive calls made to your Google Voice number within Gmail after following these instructions. You will need to install a voice and video plugin for your browser, which can be downloaded from http://gmail.com/call. 

The new calling button is integrated into Google Chat, and users can click on "Call phone" at the top of the chat list and dial a number or enter a contact’s name from your Google contacts.  This feature will be rolled out to US based Gmail users in the next few days.

Update: I got to try this feature out in my account and it worked pretty well. I tried calling my own number and several others and the voice quality was excellent.