By anyone's reckoning, it was a rough week.  Crude oil continued its relentless climb; banks and brokerages gave hints of more discouraging news; government data pointed to a weak economy; even strong companies like Nike, Oracle, and Research In Motion issued cautious guidance; and Federal Reserve policymakers, widely perceived as powerless to help, left interest rates unchanged.  But all week, even through the worst of the market's sell-offs, CNBC guests offered