Details of the iPhone’s Japanese keyboard, due to appear in iPhone Software v2.0, have been posted online. According to a TokyoMango posting accompanying the video, users will be able to choose between a QWERTY-style keyboard and a Japanese cell phone-style keyboard, and may then pick from a multi-tap style kana keyboard or a sliding keyboard. According to the post, “Japanese kana letters are organized in groups of five according to a…