Call phones from Gmail- A new feature from Google

until now, this required both people to be at their computers, signed into Gmail at the same time. Given that most of us don’t spend all day in front of our computers, we thought, “wouldn’t it be nice if you could call people directly on their phones?”

Starting today, you can call any phone right from Gmail.
Calls to the U.S. and Canada will be free for at least the rest of the year and calls to other countries will be billed at our very low rates. We worked hard to make these rates really cheap (see comparison table) with calls to the U.K., France, Germany, China, Japan—and many more countries—for as little as $0.02 per minute.

Dialing a phone number works just like a normal phone. Just click “Call phone” at the top of your chat list and dial a number or enter a contact’s name.

Rate comparison

Download the Phone software from here
http://www.google.com/chat/voice/

Watch this video for more details