We did BA-Callao with an overnight pre-cruise to Iguazu Falls and the post-cruise to Machu-Picchu. The only other tour we did was the one out of Puerto Montt to Petrohue Falls and Emerald Lake and it was a great tour. The one day trip from BA-Iguazu is a tough one, as folks who have done it will tell you. The falls are well worth the trip, but it's tough to see everything in a day, because there's a lot of walking and it can be very hot/humid. Marcie is correct about the Machu Picchu trip as far as the altitude affects are concerned. The worst part is Cuzco, which is higher than Machu Picchu. The Monasterio Hotel there is unique and the town/surrounding areas are well worth seeing. The Swiss Hotel in Lima was very nice with very spacious/comfortable rooms. I would highly recommend going to La Rosa Nautica for lunch while in Lima. You can get a hotel limo from the Swiss Hotel for $10 round trip. Great seafood and a wonderful location. Also, as part of the post-cruise tour of Lima you'll have a great lunch at Huaca Puellana, the pyramid archeological site in Lima and associated restaurant.
