Stand back! This section presents a very exhaustive list of items that you might take along with you on your next international trip, with my focus on rough travel in the Third World. If you can't find it in these lists, it may well not be worth considering. If you bring them all, you will need your own truck to get around! To calibrate reality, you will find sample Packing Lists at the end of this piece.
First, I will give some general guidelines about certain types of gear, and a sermon about traveling light. Along the way, I will be unable to resist throwing in personal anecdotes about some of these articles, to give you a better feeling for their utility or lack of it. This is a long discussion -- 11 web pages and over 300 k of text! -- but (I think) fun reading.
It's Up to You
You could seriously study the following treatise -- and dozens like it in various guide books -- as long as you like; and I recommend that you do so. In the end, you will take what you want to take. I will try to steer you away from some items, but many others are purely a matter of personal choice. Most all of the gear that I have ever taken On The Road is mentioned here (as well as lots of stuff that I would personally never carry across the street), but everyone has their own needs. I have tried to include just about everything that travelers are caught carrying around, whether I personally think they are useful or not; and I will certainly not refrain from telling you why not.
On every trip, I take along a few things that I rarely use and end up throwing out. Some of these are tagged "experimental", meaning that I want to try them out to see how useful they are. Others are just the result of vanity or lame thinking. If you have done very little traveling or backpacking before, you will not be well prepared for deciding what to take. Naturally, you will bring along several articles of questionable usefulness, which will provide endless hours of amusement for your fellow travelers when you produce them from your rucksack. We all need a good laugh out there sometimes, and I thank the novices for providing a good few of them.
Along the way, you will realize the uselessness or inappropriate nature of some of your choices and be moved to toss them out, or present them to some grateful local. This is just part of the process. You will travel lighter, you will have learned a good lesson and become a better traveler. And the local culture will have been enriched by its first aerosol can, inflatable beach mattress, or water-purifying paper weight.
"What can I buy after I get there?" You must be able to answer this question before you can do an adequate job of packing. You should also know if it will be of reasonable quality and price. By knowing what will and will not be available, you will save some nasty surprises, and avoid packing a lot of redundant gear. Unfortunately, you have no way of knowing what you will find once you get "out there"; you cannot "just take everything".
But I am now going to give you this valuable information, which can only be gathered through extensive research (futile shopping trips) at the four corners of the Earth. I will tell you whether an item is difficult or impossible to find in the Third World, and perhaps how it compares in price and quality to similar items at home. I may offer reasonable alternatives which are available. Some useful items are available only overseas, and you should allow space in your pack for them -- but you won't!
If something is generally not available, or very expensive overseas, I often decide to live without it, and don't bring any along. There is no point in getting used to something you cannot replenish. For this reason, it can be easier to pack light for a long trip than for a short one. I don't plan to bring home most of the things I take. Along the way, I will buy new clothes and replace things as they wear out. This teaches me to be more reliant on my environment, and less attached to my gear.
However, there are several items that I personally find very useful, and I try to bring enough to last me for a long time. Two examples are lip salve and good insect repellent. Although you can now find both ChapStick and DEET-type repellent in a very few large cities in the Third World, they will usually be hard to find and quite expensive. You may also notice that (like you) I have grown attached to a few very small specialized items that I like to have with me. You may not always find my information accurate; some things are available here, but not there. The good news is that "western" goods are becoming more and more available in larger cities of the Third World.
Now consider this: Some people have lost their entire rucksacks and continued on. All those precious items from home that they could not possibly live without? Guess what? -- they could live without them! They went down to the local shops, bought what they needed, and went on with their trip. Think about this, and don't get too attached to those special goodies from home.
First World Sources
If you will be swinging through Australia/New Zealand, North America, Japan, or Europe on your travels, you will be able to pick up just about anything you could imagine, including high-quality camping gear. You only have to find them.
The U.S. is good for buying high-quality camping gear and clothing relatively cheaply. The best sources are discount 'factory outlets', liquidation companies, Army/Navy Surplus stores, and regular "clearance sales" at any of the large outdoor equipment companies. They are not always easy to find or to get to. Your best source in any city is an outdoor enthusiast who knows where the cheap outlets are located, or try the telephone book.
An equally useful US source, especially for used clothing, are the various second-hand shops run by charitable organizations such as Goodwill Industries, the Salvation Army, the St. Vincent DePaul Society, and Union Gospel Missions. They are very cheap, and a good place to stock up on warm clothing that you won't mind tossing out later. Look in the telephone book "Yellow Pages" for "Used Clothing" or "Thrift Shops" in any city.
In addition to "western" countries, there are now a number of excellent outdoor hiking and mountaineering shops in Japan. They have huge selections of serious camping equipment and supplies, much of it designed and made in Japan. They have a few items you will not see anywhere else. The best is Ishii Sports, (ICI) in Shin-Okubo, Tokyo, one block from the station [The ICI Web Site is in Japanese only]. Unfortunately, anything you buy in Japan today is very expensive indeed. You will find some ordinary camping gear and clothing at a discount in the Ame-oko street market of the Ueno section of Tokyo, across from Ueno station.
Hong Kong manufactures a great deal of clothing for western countries, and there are many small shops selling "second-quality" or "last-year's" clothing, very cheaply. In particular, it is a good place to find winter clothes for heading north, because they are unsuitable for the local climate of Hong Kong (but don't expect too much in the way of serious sleeping bags or expedition gear). While the Stanley and Central sections of Hong Kong are now famous with tourists, the real bargains are on a few streets in the Kowloon City section (near the Kai Tak airport -- south of Carpenter Rd. and between Nam Kok and Lion Rock Rds.), and in the back streets of Wanchai (on Hong Kong Island), south and east of the Wanchai metro (subway) station. There is now even a guidebook in Hong Kong bookstores to help you find the cheap clothing outlets.