Google's made good on a promise today, rolling out voice calling through its Hangouts messaging service. Basically, it works just like video calling — you can call one person or many with a click of a button in Google+, Gmail, or the Chrome extension, and the wacky Hangouts effects are even in play — except it allows you to call phone numbers. You can even mix and match video and voice calling, so your friends without Hangouts won't be shut out of your chatting. Calls are free to the US and Canada, no matter what country you're calling from, and impressively cheap elsewhere around the world.

The setup works as it did in Gmail chat before the upgrade to Hangouts that removed the feature: just click a button to call a friend, or select "call a phone" and dial. It's rolling out over the next few days, and Google says there's plenty more to come: "Hangouts is designed to be the future of Google Voice, and making and receiving calls is just the beginning." Since Google's many Hangouts apps weren't mentioned in today's announcement, we're crossing our fingers that voice calling's coming to mobile next — then we won't even need phone numbers anymore.