This is a rather controversial topic. Although sharing files across the internet could be a totally legitimate way of sharing information, it is usually the primary method of piracy. Because high speed internet access is almost the standard across the civilized world now, piracy has reached all time highs. I'd like to offer my disclaimer immediately and let everyone know that I do not condone piracy. However, I strongly encourage you to read my article in reference to the Recording Industry Association of America (RIAA) and why I personally have no conscience when it comes to sharing music. Keeping in mind that I am myself a musician, I'd like to suggest that the internet and the affordability of technology is rendering record companies more and more useless every day. It is of utmost importance that musicians do NOT sell themselves short when signing a contract. They need not "sell out" as quickly as they did before. However, it is also recognized that the record companies are the gatekeepers AND the key holders of the music industry. Please, just read the article.
As for software piracy, I love to buy shareware. And I will buy professional applications like Apple's Logic Studio 8 or Adobe Creative Suite when and if I am using them professionally (to make money).
That being said; here's how to "share" files...
Peer to Peer (P2P)
Limewire is a file sharing client for the Gnutella network. What it does is this. Upon first launch, it opens up ports on your computer and establishes a "share" folder which others have access to while Limewire is running. It is known as a P2P file sharing application; that is, a Peer to Peer because one computer connects to another computer to download a desired file. What makes Limewire unique is that it is similar to Torrents (later explained) in that it will find other computers with the same file and will download that same file to your computer simultaneously thereby increasing download speeds and efficiency. This is the simplest kind of P2P file sharing. And since it is very easy for anyone to do this, it is the most common form of file sharing. It is also the most virus and spyware prone vehicle known. Bearshare is another popular service that is often referred to as the worst of all virus laden services. Another caveat of these services is that since it takes almost no technical skill, often times the files that you are trying to download either don't work, are of a horrible quality (movies and music), or are false and are actually something else (like spyware, viruses or simple adverstisments for another product or service). I will use Limewire as a "last resort." However, here is a great tip on how to share your files with someone else.
I had a client who needed to send files to one of her clients. These were huge Photoshop files that she had been working on and in order to collaborate with her client, she had to keep it in the Photoshop format. These files were about 500 MB in size. Emailing was not an option and FTP was too complicated. So this is what I told her to do: I told her to install Limewire on her machine and her clients' machine. She was to name the file that she wanted to share with her client something very obscure and long- something like "aldiwdls;aidja;diaknfiwehniw9". Obviously, no one could guess the name of this file. But she sent the file name to her client via email. When her client started Limewire and searched for that file, low and behold, Limewire began to download it. It was a quick and (very) dirty way to share a file without using FTP.
Most P2P file sharing applications use commonly known ports to function. If you are at a school or business, these ports can be closed at the router or firewall to disable these services. Keep in mind too that these services suck up a lot of bandwidth so your usage will definitely affect the whole network.
Bit Torrents
Bit Torrents require a little more expertise but it is still not that hard. All you need is a bit torrent client (like Transmission, Acquisition or BitTorrent) and a few good websites to acquire the torrent (like IsoHunt, torrentz.com or MiniNova.org). Often, doing a Google search for the file you want followed by "torrent" will garnish you a positive result. A torrent is really just a pointer to where the file is. Once you have your client open this torrent, it starts downloading the files requested. The good thing about torrents is that the more people downloading a file, the faster the download! How is this possible? Because even while you are downloading the file, the parts that you have downloaded are now being contributed to the torrent as a whole. So others can download just the parts of the file that you have already downloaded. The more people downloading the file, the more sources available to download from, the faster and more available the file downloads.
The quality of files are often better because it does take a little skill to offer a torrent. Because of this, the user knows to not compromise quality just for the sake of small file size. It is also nice to have an active forum from which you can read the posts of others who have already downloaded these files. Most times, simply by reading the posts you can decide whether or not you want to spend the time downloading this file.
Newsgroups
Newsgroups are much more complicated and for the most part, are not free- at least not the better ones. There are 4 main ingredients to utilizing Newsgroups. 1- you need a Newsreader. 2- you need to subscribe to a newsgroup. 3- you need to subscribe to a service that allows you to search for files. 4- You need a program to reassemble all of the parts of the file that you are downloading. Each of these things can cost money. I'm sure you can find a way to do it for free but you get what you pay for.
One of the ways in which a Newsgroup is judged is by their "retention" period. That is, how long do they hold on to the files before they are purged and unavailable. Obviously, the longer they hold on to files, the larger their systems have to be and the more money it will cost you. In addition to that, different services (and levels of service) will allow you to download only so much per month. Unlimited downloading comes at a premium. Often, the Newsreader will also cost money.
Here is a little history on how the newsgoups work. As the name implies, a newsgroup was for news and acquiring news. It was mostly a text format only. However, if you "encode" a file- any file- it can be viewed as a text file. Obviously, it will just look like a bunch of jibberish but once you "decode" it, it turns back into the regular file. But most newsgroups only allow each message to be up to 50 megs. This is a pretty huge text file! But as for movie files? That's not so big. So what you have to do is- take this movie (or application), break it up into small parts, encode each small part and then upload each part to the newsgroup. Now others can download all of these parts, decode them and put them back together to reform the original file. Pretty slick, huh? The problem is that if you were to miss just one file (and a movie or large application could be hundreds of files), the file would fail to reform. So then someone came up with "par" files that will "fill in the missing parts" if a small number of parts are missing. This is great! But, it takes another program to assemble these parts. I use Unarchiver. Unarchiver will read "rar" files and "par" files making it a great choice for this method of file sharing. And just to share all of my secrets with you, I use Unison as a newsreader and Giganews as the Newsgroup service. Back in the day, you had to do a lot of research to find all parts of a file. But then someone came up with the "NZB". An NZB is a file that automatically locates all parts of a given file. This makes using newsgroups much more of a convenience. However, this means that your newsreader needs to know how to read NZBs (Unison does), AND, more importantly, now you must sign up for a service that offers these NZBs. This will also cost money most of the time. I use "NZBsRUS.com".
Once you have all parts in place, not only are the downloads incredibly fast, but the quality is top notch. Often, you can find things in newsgroups that aren't available any place else. It is by far my prefered method of file sharing but again, it does cost me. And to think that this money is going towards all of these alternate methods instead of the proper people weighs a bit on my conscience. But, I get over it and sleep just fine.