I'm going to teach at the University of Sao Paolo (in Ribeirao Preto) in January and have a few (about 5) days spare to travel around Brazil. Does anyone have any suggestions? Ideally I'd love to fly to Manaus and go on a say 3-day boat trip on the Amazon or Rio Negro, any recommendations and/or web links for this? Seems quite expensive though. An obvious alternative is Rio (what to do/avoid there?). Any other ideas? Muito obrigado!