If you didn't catch the to-do recently, Viber founder/CEO Talmon Marco was nearly arrested for using his own VoIP service on a Delta Airlines flight.
Well, now Virgin Airlines will begin allowing in-flight calls over the Atlantic, and not just with VoIP. Passengers already use wi-fi for Skype, according to BBC News.
However, there are still limits. The service won't be free, you need a certain cell carrier, and it depends where you are in the sky.
Mobile access will be provided by AeroMobile, and only customers of European carriers Vodafone and O2 or the US carrier T-Mobile will be able to make calls.... In the United States, the Federal Communications Commission bans the use of mobile phones on aeroplanes, so passengers will not be allowed to make calls when approaching US airspace.
See more at Updated News (from BBC News).