http://www.macnn.com/articles/13/01/16/options.emerges.from.testing.in.canada/
Facebook extends Messenger voice calls to US
updated 04:48 pm EST, Wed January 16, 2013
Options emerges from testing in Canada
Facebook has enabled VoIP calls for US users of its iOS Messenger app, the social network tells The Verge. The option doesn't require a Messenger update; instead, people must only start a conversation with another user, tap the "i" button in the upper-right, and then hit Free Call. The person receiving the call will see a push notification.
Facebook began testing VoIP calls earlier this month, but only in Canada, presumably to take advantage of a more manageable user base. The expansion of the feature to the US could put Facebook in competition with other VoIP services such as Skype. At the same time, however, Facebook has yet to mention any plans for adding VoIP to its website or the Android version of Messenger.
