As the president and CEO of the Silicon Valley Leadership Group, Carl Guardino is probably in as good a position as any to consider what makes California?s cradle of technology the success it is. In a presentation at the Silicon Valley Comes to Oxford event at Oxford University?s Said Business School earlier this week, he offered seven key leadership lessons. But the talk ? which he billed as delivering ?the secret sauce of Silicon Valley? ? also offered a context for the style of business that has emerged in the area over the past few decades.