MarLim - We're staying at Tambo del Inka for 2 reasons: it is in the Sacred Valley (Urubamba), and it's free (well, it's 50,000 SPG points for 6 nights, which is the next best thing). At that price, I will be glad to pay for taxis from the hotel to Cuzco, Pisac, etc., each day, and keep a single (very nice) address while in that area.
SJOGuy - Since the only options to/from Juliaca/Lake Titicaca are LIM, CUZ and AQP, the only more efficient option would be CUZ-PEM-CUZ-JUL-AQP-LIM. One friend who's been to Peru twice said that he learned to save his trips to the rain forest (P.Maldonado once, Iquitos the other time) until the end of his trip, so that he didn't have to worry about his stuff getting humid, wet, etc. That's why I booked CUZ-JUL-AQP-[LIM-]CUZ-PEM-CUZ-LIM, which (if we don't go back to LIM for the night) is only 1 extra segment. (Of course, since PEM-CUZ-LIM is on an AA award, I can probably shift the dates of those segments without charge...)
All - please, keep critiquing, suggesting, etc.!