A Swiss Army Knife can be distinguished by its red casing, printed with a white shield and cross. It contains multiple layers of tools, always including at least one blade. These tools can be rotated in and out of the casing for use. A Swiss Army Knife with all tools extended looks a little like a hedgehog.
Made by two Swiss companies called Victorinox and Wenger, it was originally intended for officers and soldiers of the Swiss army. Swiss Army Knives have become an expression for versatility and portability. Today they are produced in a wide range of varieties, including all sorts of tools from a blade to a digital altimeter.
History of the Swiss Army Knife
As said above, the Swiss Army Knife is produced by two companies, Victorinox and Wenger. Based in different parts or cantons of the country, they were both awarded contracts for supplying knives to the Swiss army in order to minimise friction between the French and German-speaking parts of the country. For the same reason, Victorinox knives are identified as 'The Original Swiss Army Knife' while the Wenger ones are labelled 'The Genuine Swiss Army Knife'.
Victorinox was founded in 1884 and made its first deliveries of pocket knives to the Swiss army in 1891. Two years later Wenger made its first delivery. Because the Swiss army had just introduced a new rifle that needed a screwdriver to be maintained, the knives delivered included one. A can-opener and a reamer were thrown in for good measure. Thus, the Swiss Army Knife was born.
The Swiss army decided in 1909 to decorate both companies' knives with the national symbol (a white cross). This has ever since become the distinguishing mark that identified the true Swiss Army Knife, be it 'original' or 'genuine'.
In 1921, Victorinox switched to stainless steel for producing the blades and tools. Sources on Wenger are inconclusive, but it is likely that they made the switch at about the same time.
From 1945 till 1949 the versatile knives were available in American PX stores. They probably sold very well, as from there on the original (or genuine) Swiss Army Knife has diversified into over 800 different forms. Both companies have become huge and are exporting incredible amounts of their products all over the world.
Choosing your own Swiss Army Knife
Swiss army knives are not exclusive to the Swiss army today, and nor have they ever been, really. Everyone and their sister can own one, and probably does. They have many uses, and buying one entails choosing the right one. They come in many shapes and sizes nowadays, so you will have to take a good look at what you want from your pocket knife.
If you want it to fit in your pocket, without making everyone think you are 'very glad to see them', you will have to compromise in the tools included. Also, some of the tools that can be found might be of little use. If you are not planning on going mountaineering, why buy one with an altimeter? If you are a severe technophobe, would you need a screwdriver?
Take IT professionals for example - they're not necessarily mountaineers or survivalists. Because their jobs and possibly hobbies entail unscrewing computer casings, among other things, a knife that has not one but two screwdrivers might be a good choice. It could also have a small magnifying glass for identifying those tell-tale burn marks on dead or dying computer hardware. Of course, it would have to have the ubiquitous blade, can opener and corkscrew. An IT professional's ideal knife would probably have embedded in the side plates a pen for writing down technical things, a pincer for manipulating tiny parts and a toothpick for occupying the time while listening to clients' complaints.
Dos and Don'ts
Do take care of your knife, clean it once in a while, and keep the blade sharp.
Do use the knife; it's not intended as a novelty item. If implements on it aren't particularly useful, trade it for a more useful one.
Don't use your knife to try and impress people. Such knives are functional tools, and having one just as a fashion accessory might make you look silly.
Don't use Swiss Army Knives to hurt people. It's illegal and highly antisocial to do so, and the blade would probably break too.