Just returned from a quick trip to Peru (7 days), here's some info for anybody else planning a trip. I'll stick mainly to logistical details; if you're interested in more of a storytelling approach feel free to check my trip blog. We had no advance reservations or bookings for any portion of this trip except for our flight home.
Money - had mixed experiences with ATMS in Peru in terms of maximum allowed withdrawal amounts - the one at the Cusco airport maxed out at 300 Soles ($100 USD), the best one we found in Cusco maxed out at 700 Soles ($245 USD).
Cusco to Aguas Calientes - don't believe the hype about the train from Cusco - do it cheaper by taking one or two colectivo taxis to Ollantaytambo, and catching the train from there to Aguas Calientes (its cheaper and more frequent). Colectivos can be either a minibus or a small toyota sedan/hatchback car - some drivers offer to take you straight to Ollantaytambo but the more common route is one hop to Urubamba and then a second hop from Urubamba to Ollantaytambo. The going rate for a four-person colectivo one way Cusco to Urubamba is 40-50 Soles; from Urubamba to Ollantaytambo is 20-30 Soles - divide by 4 to get the per person cost, or just offer about that much in total if you don't want to wait to pick up any more people. That portion takes only about an hour and half.
Ollantaytambo is a nice en route stop - very quaint (but very busy with tourists), the ruins are quite significant in Inca history and are also impressive. Last train to Aguas Calientes leaves around 10PM, gets to Aguas around 11:30/midnight. We stayed at Hospedaje las Bromelias (50 Soles for a double room with private bathroom), which is right in the corner of the plaza and had very helpful and friendly staff.
Aguas Calientes to Macchu Picchu: We opted for the hiking trail over the bus, leaving our hostel at 5AM, in the dark and in the light rain (torch/headlamp is essential). Hike was more or less straight up for about an hour and a half, definitely an invigorating way to start one's day! We arrived at the main gate of MP around 6:30, and were somewhere between #250 and #300 in line. Several busloads had made it there before us, those at the front of the line had been queuing in Aguas for the bus at 4AM. Fortunately as we were within the first 400 we were able to get a ticket to access Wayna Picchu, we chose the 10AM-12PM access time hoping the fog would burn off by that time.
What can I say other than to endorse MP as a sight to see, its scale, location, and state of preservation definitely make it stand out among Incan ruins. For Wayna Picchu, they are pretty lax about the time limits - we started about 40 minutes before my designated time without much of a problem. Its another very steep climb with some tiny steps and some clambering; it takes about 45 minutes up if you move at a good clip, and once up there it was shocking how small MP looked. It took us about 5 hours to get our fill of MP, we left around 12PM in order to have lunch and catch the 1:15 train back to Ollantaytambo. Recommend bringing plenty of water with you into MP, and sneaking some food/energy bars - we may have misheard but pretty sure there are no ins&outs at the main gate.
Cusco - though we had some trouble getting a hotel on walk-up, we found but cannot recommend the Hostal del Inca on Quera street, 80 Soles for a 'matremonial' room (1 double bed) - limited hot water and accusing us of room damage were just two negatives.
Central Cusco, while small, is still kind of a hard town to walk around in...traffic seems to be going non-stop in any given direction on any street. Nonetheless we attempted to make the most of our Boletos Turisticos and hit up Saqsaywaman (very important in Inca history, though sadly not much left), Pachaeutec monument, and Qorikancha museum (notable only for a mummy in there...not sure its even real though). Each night we were in Cusco, there was some kind of celebration going on in Plaza de Armas, so definitely make sure you stoll through there regularly.
We booked a day rafting trip through a helpful and agent company (Andina Travel) at $40USD total per person. The actual operator was Mayuc, they have an office on Plaza de Armas where you can book direct as well. Though the water was near a low point, it was still a good day out with plentiful Class II-III rapids, great and fun staff at Mayuc and - perhaps most importantly - they have a base camp with a sauna, which was key after getting out of the cold river.
From Cusco to Arequipa: There are literally tens of bus companies that ply the Cusco-Arequipa route, including some that have 100% full cama (like 1st class airline) seats. DO NOT believe the travel agents in Cusco that tell you Cruz del Sur is the only option! If you do take Cruz del Sur from Cusco to Arequipa, be sure you verify the departure location - some buses leave from the Cruz del Sur office, not the bus station - and these two places are in different areas of Cusco. Of course we were on Cruz del Sur (semi-cama for 90 Soles per person), and the bus stalled many times overnight, culminating in a final breakdown just 10 minutes from the Arequipa bus station.
Arequipa - we stumbled across a great find for a hotel in Arequipa called La Casa Blanca, 412 Jerusalen - highly recommended...it seemed very new (or was just really clean), had free wifi (and a lobby laptop to use), a small courtyard cafe, and bar on the property - cost was only 70 Soles for a double room. The tour agency within (Your Peru) also booked us a good deal on a one-day Colca Canyon trip, only 45 Soles per person (this was about half of what we were quoted elsewhere).
Our Colca Canyon daytrip with Colonial Tours definitely exceeded expectations. Our guide Irena was fantastic - she kept up the energy, information, and humor on a trip that started with a 2:30AM pickup from the hotel and ended around 6:00PM. We were lucky enough to spot 3 condors in the canyon. The buffet lunch spot we stopped at was also quite good - for a very reasonable price, around 25 Soles, got the chance to try all kinds of different Peruvian food including cuy (guinea pig). There were other options for those who wanted to skip the buffet.
On the day of our departure we did a downhill mountain biking trip booked with the Ecotours agency (Jerusalen 409), cost was a bit steep at 150 Soles per person, but we were the only two going so didn't have a lot of bargaining power. Our guide was pretty good, the bikes and safety equipment were in decent shape, and we started pretty high up on the hill so had a good two hours of descent across dirt roads, smaller trails, and paved road. On some sections (including the little uphill grade there was), the road got too sandy to ride. The trip lasted from 8AM to 2PM, which makes it a good candidate to do on a getaway day. We finished the day with a visit to the Monestaria de Santa Catalina, which seemed a bit pricey at 30 Soles, but was an interesting place to explore and at least had some signage to explain what we were seeing.
Arequipa to Lima - like the Cusco-Arequipa route, there are many other bus company options available but we went with Cruz del Sur because that was the only one we knew the website for...we paid 79 Soles for a semi-cama seat on the 16-hour trip. The bus we took was an 'Imperial Tour' type, which means all semi-cama seats. If it is a cama you seek, check out a company called Excluciva - they run buses with 100% camas - one floor has 150 degree recline and another floor has 180 degree recline - Arequipa to Lima they run 2 of these per day, departing at 4:30PM and 6PM.
Lima - we splurged on a hotel in Lima, staying at the Lima Sheraton on hotel points. It was what one would expect from an international chain hotel, definitely no problems with hot water or cleanliness. It was a bit hard to orient ourselves in Lima, being so much larger than any other city on our itinerary.
We made a quick trip to Miraflores, enjoying the ocean breezes, cliffs, and sights of the paragliders...and passing on the chance to dine at Chilis and Tony Roma's restaurants there at the big cliff-top shopping mall. Fortunately the Sheraton runs a free shuttle from the hotel to Miraflores and back, once an hour - though they never asked for proof we were staying at the Sheraton so if you want a cheap way to get to Miraflores I'd recommend it!
In central Lima we spent quite a bit of time strolling through the pedestrian shopping mall that leads to the Plaza de Armas, doing a bit of people watching and snacking, as well as last-minute souvenir shopping. Visited the Cathedral de Lima primarily to see the remains of Pizarro, but left a little underwhelmed. Big recommendation for the Monestario de San Francisco (the one with the catacombs) - great free guided tour and the library was a sight to see (no pictures allowed though, darnit!).
Taxi from central Lima to the airport was about 90 Soles (this was the 'posted' price at the hotel, I'd imagine if we flagged one down elsewhere it would have been cheaper), definitely budget an hour just in case, traffic was crazy even at midnight! Oh yeah, and if you happen to lose the tiny half-sheet of paper from your Peru entry form (filled out upon arrival), they charge you at the airport to replace it (think it was 5 or 10 Soles) - so put that in a safe place when you arrive!