South American Ports, what's the best to do?

[rastewa]

Hi all, we're on the Radiance, coming from Valparaiso, Chile to San Diego Leaving April 26th. With stops at La Serena, Chile, Lima, Peru and Manta, Ecuador. What would be anyone's recommendation for these ports other then the ships tours? Am I correct if saying in Lima, it's a must to take a guided tour if you wish to see the city? Has anyone ever used one of the other tour companies from the internet? There seems to be alot. Would there be taxis or small tours buses at the port that one could enlist for the day? And the same for Manta? It appears there would be nothing immediately off the ship. Anyone ever stop at these ports and has any 'insider' information?