A scientific colleague recently blogged tips on finding full-text scholarly articles online (see the full series from Sandra Porter's blog Discovering Biology in a Digital World: Part 1 ... Part 2 ... Part 3). Several other colleagues posted comments, and there are some great suggestions (including limiting a PubMed search to articles with full-text). But no one mentioned the library. I posted a reply explaining how librarians could help. Here's what I said, in case it can help others:
A great resource to start with is ... a great librarian. Hopefully you have one at whatever institution you're affiliated with and they can tell you how to access their resources from off-campus. It can involve a quick trip to the library's web site, a search through their journal locator, and then a login with your institutional id & password. It's somewhat cumbersome, but it can definitely save money!
Also, if you're affiliated with an institution, you can request that they get you articles you want by Interlibrary Loan -- that means that your library will ask another library to send the article by pdf to them & they'll get it to you. This will work at a college or corporate library -- and your local public library will probably do it to. For free!! (that is, no cost to you).
Beyond that, here are some additional tips:
The Directory of Open Access Journals (DOAJ) is a great place to find free scientific articles online. Much of this is in PubMed I think, but probably not all. Here's what the DOAJ says: "This service covers free, full text, quality controlled scientific and scholarly journals. We aim to cover all subjects and languages. There are now 2,701 journals in the directory. Currently 806 journals are searchable at article level. As of today 134,219 articles are included in the DOAJ service." You can search for articles or find journals by topic, title, or search.
The science search engine Scirus can be very handy. At their advanced search page, you can limit your search to discipline, scientific article, publication date, or web site. Unfortunately, you can't limit to full-text articles, as you can in PubMed.
Finally, you can tweak your Google searches to increase the chances of getting the full-text: Use quotes around the title of the article to exclude results that have the words in the title of your article but aren't that article: speech perception in infants vs. "speech perception in infants", e.g. Another great trick in Google is to limit by filetype; since most of the articles you want will be in pdf format, you can limit your results to those that are in pdf, with the command filetype:pdf. This will eliminate results which reference your article in a bibliography but don't actually have the full-text.
This search "speech perception in infants" filetype:pdf yields 1220 results, rather than the over 10,000 results from a search on the title alone.