If you haven't done so already, I encourage you to check Tim's entry on Protesting the Empire as Obama visits.
The US press didn't cover many of the protests that greeted Obama during his trip to Latin America. Honestly, I don't think that they covered much of his trip at all, especially the television media. There was a Miami Herald article last week that said the same thing. It was from the Spanish edition, but I haven't been able to relocate it.