I have been using Skype for all of my international calling for almost 3 years. I was coordinating a trip to Europe and discovered that most of my European calls on Skype were around $0.02/minute compared to over a $1/minute from the local telephone company. When my brother’s family moved to Japan, Skype got even more use. I find the quality as good or better than a traditional phone.
So I am not surprised that Skype now accounts for 8% of the worlds international calling minutes. You can even record your skpe calls.