BusinessWeek reports that Microsoft Corp. will start selling its Kin mobile phones online tomorrow May 6th with Verizon Wireless, the biggest U.S. mobile-phone carrier. The Kin One will sell for $49.99 after a $100 rebate and a two-year service contract, the companies said in a statement. The Kin Two, with a larger screen and higher-resolution camera, will cost $99.99. Both phones go on sale in stores on May 13.