When Big Blue celebrates its centennial later this year, it will do so in style. Sales reached almost $100 billion in 2010 and profits, which have quadrupled during CEO Sam Palmisano’s nine-year reign, hit a record.The secret: a heavy focus on innovation. IBM spent $24 billion on R&D last year and filed over 18,000 patents — more than any other company in the world. Most firms pulled back during the recession, while IBM invested big in projects like artificial intelligence (who didn’t watch Watson on Jeopardy?) and Smart Planet, its plan to use networking computer technology to ease traffic congestion and overtaxed power grids. —P.N.