Facebook CEO Mark Zuckerberg says Japan’s massive tsunami inspired him to seek more ways for his social network to help people hit by natural disasters. Zuckerberg, who is visiting Japan, told Prime Minister Yoshihiko Noda that he believes Facebook can be used to help people in disasters keep in touch and provide them with crucial information. He did not go into details during the brief meeting Thursday. Noda expressed his appreciation and said he felt odd meeting the young entrepreneur after seeing the hit movie “The Social Network,” which was based on Zuckerberg’s life and the legal problems he had with others during Facebook’s early days. Laughing, Zuckerberg said the Hollywood portrayal of him wasn’t completely on target. “Very different,” he said. … Katie Couric helped start and perpetuate morning television’s most epic winning streak. Now she’ll try to break it. ABC announced Thursday that the former “Today” show anchor will be guest host next week on “Good Morning America,” the rival wake-up show that has been rising in the ratings. She will sub for the vacationing Robin Roberts for a week, teaming with George Stephanopoulos. Couric was co-host of “Today” in December 1995, when the NBC show’s streak began. “Today” has won every week in the ratings since then, 850 consecutive and counting, according to the Nielsen company. Yet frisky “GMA” has been making noise lately. Last week the ABC show was only 137,000 viewers behind “Today” (an average of 4.98 million to 4.84 million), the closest the two shows have been since 2008. … Ernest Hemingway shows a tender side in previously unpublished letters being made public by the Kennedy presidential library in Boston. In a letter to his friend Gianfranco Ivancich written in Cuba and dated February 1953, Hemingway writes of euthanizing his cat Uncle Willie after it was hit by a car. The author writes: “Have had to shoot people but never anyone I knew and loved for eleven years. Nor anyone that purred with two broken legs.” The letters span from 1953 to 1960, a year before the prize-winning writer’s suicide.