Ringplus is a new phone service in beta testing that is giving free international and long distance phone calls. There is no obligation since they don’t need credit cards
They are getting money from ads by replacing the ring tone so the advertisers bear the cost of the call. Access numbers are given for major cities at this page.
It is worth giving a try to call international or US national numbers to get this free deal. It is reported by some users that they get close to 60 free minutes for calling India. some users are complaining that the infamous message “All circuits are busy” is heard many times.