that's a great post. one possible way to avoid the noise in lima, stay near the coast. i stayed up on the cliffs overlooking the ocean and noise was not a problem at all. quite and beautiful. highly recommended.

also, re: airport time. i took a morning flight - likely one of the first - and lines were not a problem at all. i think in any airport your chances of getting out on time and avoiding lines and backup are better the earlier flight you schedule.

A couple of notes:

I was in Peru in June 2007. I am a water hog and was worried about being able to buy water at the airport for the flight back to the U.S.

They told us that any bottles purchased after the security check for use on the plane had to be sealed by the shop that sells it to you. I bought one bottle to drink at the airport and one for the plane (which they sealed in a big vacuum-seal bag). But when we boarded the plane, no one even checked my water (unlike flying back to the U.S. from Beijing, where I had to sneak my post-security water purchase in the depths of my carry-on).

As for altitude sickness, in our group of 12 only a few people felt any effects. We flew to Cuzco but then took a bus directly down to the Sacred Valley, and I believe that helped quite a bit. Also useful: Staying hydrated (REALLY hydrated), using over-the-counter headache meds, and partaking of the coca tea that was available in every hotel lobby at the higher altitudes.

Also helpful: Taking lots of one-dollar bills. I used soles for purchases, but dollars were also accepted at every street market.

I wish I had budgeted better -- my ATM card did not work down there, and my cash was so tight toward the end that I didn't have enough to buy all that I wanted to on the Uros Islands on Lake Titicaca at the end of our trip. Not only were the handicrafts pretty neat, but tourism is the main source of income for the tribe and I wanted to be able to help.

Oh, speaking of shopping, one more tip: Our guide for Machu Picchu told us that if we wanted to buy T-shirts that said Machu Picchu on them, to do so in the market that leads up to the train station in Aguas Calientes. He told us that we wouldn't be able to find them anywhere else, and he was right!

And if you want to see MP in the morning mists but can't handle the four-day trail, there are early buses available to take you up before sunrise. Our group was there the day before the solstice and took a bus up before 6 a.m. We got to see the mountains and ruins emerge from the clouds and the mist -- it was AMAZING. Every moment revealed a new vista. I would recommend being at MP for sunset one evening and sunrise the next morning -- the slanting, golden light made it an even more gorgeous place.

On ATM's. I nearly had a panic attack when my ATM card worked at the airport, but not in Ollantaytambo. What I found was it did not work in the most common ATM (global net), except at the airport, but worked great at BCP. Then I found another type of ATM in a bank just down the street from the hotel, so my panic subsided. Don't give up on the first machine. My daughter's ATM card worked everywhere. Who knows!