Web phone service provider Skype gained another key partner this week with the formation of a strategic alliance with KDDI Corp., the second-largest wireless carrier in Japan, through which KDDI will roll out two Skype-enabled smart phones next month. Skype, which currently boasts more than 560 million registered users worldwide, has agreed to integrate its web calling software with two Android-powered KDDI smart phones—the “IS01” and “IS03.” The built-in software will enable KDDI subscribers to make unlimited Skype-to-Skype voice-over-Internet calls, both domestically and internationally, through the low-cost Skype-Out service, which will transmit calls via the KDDI network. Such calls will not be charged against the monthly service plans of KDDI customers, and a KDDI official said that his company will “work closely with Skype to extend these benefits beyond mobile to broadband, fixed line and cable.” Among other benefits, purchasers of the Skype-enabled handsets will also be able to send and receive instant messages and check other users’ online status with the Skype application running continuously in the background. Expanding its influence in the U.S. and worldwide, Skype has also forged recent partnerships with Verizon Wireless and with Avaya, Inc. through which Skype and Avaya would jointly develop IP products that are aimed at the business communications market. As KDDI senior vice president Takashi Tanaka applauded the agreement as “a breakthrough in giving customers in Japan unlimited, global communications options,” Skype interim CEO Adrian Dillion declared that “KDDI’s position as a leading network provider . . . that offers a wide range of communications services makes it a natural partner for Skype.”