New York Times: Steve Jobs simultaneously led two companies, Apple and Pixar, as chief executive. Elon Musk is running Tesla and SpaceX. Now more people are saying that Jack Dorsey can permanently run two companies at the same time, too. Dorsey, 38, is the chief executive of Square, the mobile payments company. He is also the interim leader of Twitter, which is searching for a new chief. Some investors of both Twitter and Square are now proclaiming that Dorsey is the right man for both jobs.