ResearchGateResearchGate is a commercial scholarly network (similar to LinkedIn) which includes education, employment, and, most importantly, publications. Many people use ResearchGate as a repository for publications (be careful of copyright!) and full text versions of articles are included in Google Scholar.
An account is worth it for being able to download posted articles found via Google Scholar, if for no other reason. You can also ask questions, follow other researchers, and receive suggestions for further reading