Google has launched its Gmail voice and video chat function, which enables users to call phones from their Gmail chat account.

Currently, the function is only available to US-based Gmail users, but will be functioning in other countries shortly.

“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,” said Robin Schriebman, software engineer at Google.

Calls to the US and Canada are free for the remainder of 2010, while calls to other countries will be billed.