PORT OF SPAIN, Trinidad --  Crews in this Caribbean capital are cleaning the streets, spiffing up hotels and corralling the homeless into shelters -- out of sight of visiting dignitaries who will arrive this week in advance of the Fifth Summit of the Americas, which starts Friday.

It is the hemisphere's largest and most important gathering of democratically elected leaders in years, and President Barack Obama's introduction to the region in a climate of global economic crisis. He will share the stage with 33 of his counterparts.