Telegeography has an interesting report, with the accompanying bar chart (click to see a larger version of the graphic), showing recent trends in the annual growth of international long distance (ILD) service versus Skype. Keep in mind that these are growth rates, and not actual growth, or volume of traffic. International long distance services continue to grow, but at a much slower rate. As the graphic clearly shows, the crossover point at which Skype's growth exceeded ILD was in 2009. That was also the year that "smart phone shock" hit South Korea and mobile broadband continued its rapid diffusion worldwide. Skype and similar services are even more convenient when loaded on a mobile device. These developments clearly portend a future in which the majority of people will prefer VOIP services like Skype for most of their voice communication. One of my friends who works in the communications field just wrote me that he's been happily using Skype for seven years now. Of course, you can't beat the cost of Skype-to-Skype calls!