Google's VoIP service in Gmail will remain free during 2013 in the US and Canada, thanks to a decision by Google. Google announced the news of the extension on the Gmail blog earlier today.
This will be the 3rd year of free VoIP calls through Gmail. Personally I have only used the service a few times when my cell phone was dead or not within reach.
"Gmail voice and video chat makes it easy to stay in touch with friends and family using your computer's microphone and speakers. Calls to the U.S. and Canada arefree for at least the rest of the year and calls to other countries will be billed at very low rates."