Silicon Valley is rife with companies famous for their technological innovations???Hewlett-Packard, whose founders essentially invented the valley's high-tech culture; Xerox, in whose famed Palo Alto Research Center lab was born much of the foundation for today's personal computers; Intel, whose co-founder Gordon Moore prophesied the huge technological gains of the last three decades???the list goes on and on. One company that would make almost no one's list of great innovators, Symantec, is in the midst of a quiet technological and cultural makeover designed to change that perception and cement the company's spot atop the security industry. Executing on a strategy of innovation and acquisition is Big Yellow's challenge.