Luggage and bags Definitely pack light, but dont leave out necessities! A smart tip would be to put all your clothes into sealable baggies it keeps bugs out and also moisture... at night it is a good idea espically if it rained that day to take the soles out of your shoes and open them as much as possible to allow the moisture to dry as much as possible. Your feet are the most important thing while hiking.... If your feet get wet and or blister it will make the hike miserable. Also smart packing idea- duct tape.... roll a good amount onto a pen or something... jsut to have.. a girl we were hiking with her sole came off her shoe- which my duct tape came in handy for also GREAT for blisters....
Clothing/Shoes/Weather Gear Like I said about taking the soles out of your shoes at night to dry them out. Make sure your shoes are in good condition... very important your feet are in the most comfortable and best health, so to speak!
Toiletries and Medical Supplies I brought along Wet naps.. best thing I did... Since you can only shower on the third day they made for a great morning and evening wipe down... Really kept me feeling my best to at least wipe the dirt and rain from my body at the end of the day.. Also Toilet seat covers were nice to have (when there were toilet seats..) and toilet paper, there was rarely any place if any that I can remember that had toilet paper. I also brought along and took as a precaution imodium, there were two people on my hike that were ill from the food and or brushing their teeth with the water. DO NOT brush your teeth or even rinse your tooth brush with the water. IT WILL make you sick... and taking imodium before meals - I was completely fine and rarely had to use the restroom... which when you see what some of the areas to use the restroom were like- I WAS THANKFUL!
Photo Equipment bring extra batteries and film... you may want to do resesarch on film and fog... it was often foggy and the film once i got it devolped just didnt do it justice.. you may want to see what the best options are for fog and hazy conditions so your photos turn out great... And when you make it to the sun gate.. if it is foggy and you dont have your first view of Macchu Picchu- my suggestion is wait a little while.. we had heavy fog and couldnt see it waited about 20 minutes and it began clearing. well worth the wait
Luggage and bags If you are trekking and want to bring your own sleeping bag, just make sure it is cold weather specific - meaning, that it is adequate protection for 32F degrees (0 degrees celsius? Sorry - not up on my metric system!).
Another alternative which worked for us under some unexpected circumstances, is to RENT sleeping bags from any of the better looking travel agencies that are conveniently located in Cusco, almost all within walking distance of the hotels. Getting a good thermo bag is worth the investment whether you make it before you get to Peru, or after you arrive in Cusco. I don't remember what the daily rate was for our bags, but I don't recall it being too bad.
Miscellaneous I recommend using a Camelback pack because it's lightweight and easy to carry on your back, and it holds up to 2 liters of water. I didn't have one on this Peru trip, but David brought one along for our Annapurna Trek and I was jealous!
Miscellaneous It's always a good idea to bring along a small flashlight on any type of hike. The Inca Trail is no different. Should you feel the urge to "go somewhere" during the middle of the night, your best friend will be that little flashlight! It also comes in handy if you need to make your way to the bathroom while staying at an eco-tourism lodge in the Amazon rainforest. A hat-light is another option which is really useful because you wear it like a headband, allowing your hands to be free.
Miscellaneous Unlike trekking through the Himalayan Annapurna Sanctuary where one often goes through villages where the locals have learned to provide such "amenities" as toilet paper to the passing backpacker - there aren't really any villages along the Inca Trail. Consequently, there are few opportunities outside of that first day, where you'll be able to access toilet paper. So bring along a roll or two, because you'll need it on the trail.
Toiletries and Medical Supplies The good news is, you'll be getting in some great physical exercise if you do the Inca Trail trek. The bad news is, this trek lasts 4 days, during which time you will NOT be showering or otherwise bathing. If you go with an outfit or small group, then the porters will provide boiled water in the evenings and in the mornings so that you can splash around or at least brush your teeth. I recommend bringing along some pre-moistened towlettes or wipes, to help with some spot checks and clean up jobs in between!