A large part of published scientific literature is now trapped behind paywalls. Even research that is completely funded through government funds is frequently published in journals that require incredibly expensive subscriptions to access. However, often, with a little work and luck, one can access the full text of these subscription journals and papers for free.
As a physician I have to refer to medical journals very frequently. Often my institutions have ways of accessing journals for me; however, to most people in the public, these full-text papers and journals are blocked. There are a few ways of accessing these papers for free.
1. Email the original author. The majority of authors that publish a paper are not only willing to send you a copy but will also be willing to discuss the paper with you. In your email, explain why you are interested in the paper and how you plan to use it. I speak with authors all the time that are more than happy to email you a copy of the paper. Always email the “corresponding” author if that can be determined; otherwise, the first author is your best bet. If you do not have access to the email of the author, you will at least have the name and institution from the abstract. From here, a google search or two should yield a way to contact the author.
2. Try to google the paper. Often copies of articles will be distrubuted in multiple places. For your google search place the title in quotation marks for focus your search. Adding filetype:pdf will focus your search on pdfs only. For example, here is a rough google search for pdfs from the New England Journal of Medicine: nejm filetype:pdf Some people have had luck with google scholar as well.
3. Visit or Ask your library. Almost all libraries participate in article and journal exchanges. Email the abstract to whatever library you are a member. Most of the time the library staff can find a way to get you a copy. Even if you are not a member, most libraries have public access. Just walk in and start using a terminal!
4. Flex your alumini muscles. Even if you are out of college, many libraries will grant access/privledges to alumini. As most colleges have large subscriptions with multiple services, such library access can be very valuable.
5. Free databases: If you are just looking for information and not a specific paper, you can search through the Directory of Open Access Journals or HighWire at Stanford. arXiv.org gives great access to papers dealing with the fields of Physics, Mathematics, Computer Science, Quantitative Biology, Quantitative Finance and Statistics. Biomedical papers may be found at pubmed central.
6. Take advantage of a free trial. A free trial with an online library service such as Questia can be very fruitful. Email services such as gmail can be used to generate as many email accounts as needed.
7. Try an online request forum such as livejournal article request
All the nice hacks I used to use to access papers behind a paywall no longer work; however, at least with a little work and searching, these hints will give you a chance to save a lot of money on subscription fees. If you have other ideas or tricks, please leave them in the comments.