Kicking off its huge San Francisco event Apple CEO Tim Cook told the packed auditorium that Mountain Lion OS X is the fast-selling operating system it's ever had. He added that the company's family of notebooks have now ranked number 1 in the US for the last three months, grabbing a 27 percent market share. This equates to an additional 15 percent of growth since last year, compared to a slightly more modest two percent growth in the PC sector -- Apple has outpaced the PC industry over the last six years.Filed under: Desktops, Laptops