I may have confused things a little earlier. Skype offers a international unlimited calling plan to certain destinations. That is from Skype and anyone can buy it.

ATT has international global data roaming plan available for $70 a month to certain corporate subscribers ("FANs"). At one time, it may have been open to the general public. I don't know. Folks who have that international plan and a good VOIP service will be able to make free Voice Over Internet calls in a number of countries (assuming the local networks support a decent quality call).