Video chatting in Hangouts is busting out of Google+.
Video calls among two or more Google+ users was the big draw when Hangouts launched, but now Google has flipped the switch the allow Google+ users to make phone calls to almost any phone number, not just within the Google+ ecosystem. That means that users will be able, for example, place a voice call from their computers and reach friends or family on their land line or cell phone.
The feature is limited to outbound calls and cannot accept incoming calls to your Google+ account. It's also currently desktop-only, and isn't compatible with Google+ on mobile apps.
Calls to phone numbers in the U.S. and Canada are free, and callers can buy credit to dial out to international lines.
To place a call, click the "Invite" button in Hangouts, then the "+telephone" link. After entering the number, hit "add." The dialer currently stores one number at a time.
The Google Voice platform powers the entire operation, though the feature bears the Google+ Hangouts name. You can similarly place calls to land lines and mobile phones using Google Voice's integration into Gmail.
Calling out with Hangouts is a third high-profile experimental feature that Google has pulled into the mainstream product, along with screen-sharing and support for Google Docs.