Gmail users have been chatting through PC microphones and speakers via a service called Google Talk since 2005. But until now Gmail users couldn't dial into landlines. Both Gmail users had to be sitting behind their computers and signed into Gmail to talk.

"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?'" Google Software Engineer Robin Schriebman wrote on the Official Google Blog. "Starting today, you can call any phone right from Gmail."

Cheap International Calls

"We've been testing this feature internally and have found it to be useful in a lot of situations, ranging from making a quick call to a restaurant to placing a call when you're in an area with bad reception," Schriebman wrote.

Calls to the U.S. and Canada will be free for at least the rest of the year, Google said, and it promised calls to other countries will be billed at very low rates. Schriebman said Google worked hard to make international calling rates "really cheap." Calls to the U.K., France, Germany, China, Japan -- and many more countries -- are as little as two cents per minute.

Skype's Headache

Rob Enderle, principal analyst at the Enderle Group, said Google has launched a solid Skype competitor that's tied into voice mail -- a converged offering. As he sees it, Skype should be worried because the service makes Skype redundant for Gmail users.

"This is the problem that conversion represents. A lot of folks are going to want their communications products all in one bundle. They want to use one contact list and do everything from there, from e-mail to calendaring to making a phone call; it just makes life a whole lot easier. The service that doesn't offer converged communications is odd man out when the music stops," Enderle said. "So Skype should be very worried, both because of the trend and because Google is leading it."

Google is rolling out the feature to U.S.-based Gmail users over the next few days. Users will know they are ready to chat when they see the "Call phone" link in the chat list. Users will need to install the voice and video plug-in.