Bill Gates had laid low so far throughout the financial crisis, but one of the world's richest men and leading philanthropists emerged yesterday with some advice for President-elect Obama: Spend more. In a speech at George Washington University, Gates said we need deficit spending to stimulate the economy and help the needy. He also said his foundation will increase its number of grants next year, despite declines to its $35 billion endowment, and called on Obama to make good on his campaign promise to double foreign assistance to $50 billion. Gates added that the crisis could stimulate innovation, much as the technology boom that birthed Microsoft followed the 1970s' economic woes. "Difficult times can launch great ideas," he said.