Ok.. so unfortunately, I'm starting to get a little paranoid after hearing some wonderful taxi stories... so I've done a little searching for safety in Peru.. here's what some people have said: (EDIT: now with comments after being here for a few months)
I would also suggest you leave the SLR home and take the smallest, least obtrusive camera you can find. Peru is a very poor country, with rampant theft, and it is wise to be extremely discreet with flashing anything electronic, or in the way of jewelry, because it is not at all unheard of for people to just come along and rip things right off of people's bodies. Your camera will be much safer if it will fit in a pocket inside your jacket without showing, and if you can use it without it being visible to most people around you.
Leave your jewelry home, too, at least anything gold. If you need a watch, I'd suggest taking a cheap Timex you don't care about in case it gets stolen. If you *must* take electronics like a Palm with you, keep them hidden someplace that can't be reached if someone slashes your bag, and only take them out discreetly and in private, where they will be likewise out of reach of others.
this is true... i would say be as discrete as possible with valuable belongings
Likewise, keep most of your money, your passport, and other valuables you cannot leave behind (like credit cards) in a money belt inside your pants, and only keep small amounts of cash readily accessible on your person. If you need to access the contents of the moneybelt, find someplace private to do so, if at all possible, but at rock bottom minimum, find yourself a back corner of the store or stall and face the back while you carefully access it.
since i'm here for 9 months I find it a bit unnecessary to carry around my money belt with me everywhere.. so actually since my second weeek here, i've left passport/cc/etc at home
I know that there are now some wifi hotspots around, notably in the Miraflores district in Lima, but I've spoken to many people who *live* there who won't use their laptops in public because of the extremely high risk of having them ripped off, so I wouldn't even bother taking something like that with you. There are actually a surprising number of Internet cafes around, and many hotels and even hostals allow guests to use the Internet.
I have not taken my macbook anywhere outside my house
If you're carrying any kind of pack or purse, learn to carry it on your front rather than your back, or make sure it's one that's completely lined with metal mesh that can't be cut - both would be ideal. When riding in vehicles, make sure it either goes in a closed trunk (not the open back of a station wagon or hatchback), or rides *under* your legs, and as far under the seat as is humanly possible.
I don't know that I'd do things like hitchhike (*I* certainly wouldn't do that anywhere myself), but I'm a woman and I travelled alone all over Peru and had no problems. I also did most of my travelling in daylight, on reputable public transit - a good busline for the one bus ride I had, and by air the rest of the time. Except in Cuzco, I also had private guides everywhere I went, who met me as I arrived in each location, prearranged by my friend's travel agent in Lima. They're very cheap, and well worth the investment anywhere you go.
I would *particularly* recommend you hire a guide when you go to Chan Chan, because the place is colossal, there isn't much in the way of signs, and it would be extremely easy to get lost and never get found again. And you do *not* want to be wandering around alone in there - danger, Will Robinson! Don't miss the temples of the moon and sun, and especially the tomb and museum of the Lord of Sipan in the same general vicinity while you're there.
didn't have a guide at chan chan and it was fine, there are little kiosks with info and little fish signs that guide you all the way through... didn't have a guide for huacas or the museum of Sipan either...
And oh, yes, make *sure* you carry toilet paper. There is virtually none to be found anywhere in public restrooms throughout the country, except in the better restaurants and hotels. It's not even available for sale upon entry in most places as it is in some countries. Carrying a few Wet Ones is also a good idea, because soap is equally scarce.
Despite the high theft rate and the abysmal economy, the Peruvian people are wonderfully warm and welcoming. Take good safety precautions to guard your valuables, and don't do anything stupid, and you ought to be pretty safe.