MyBib - A new FREE citation generator.
Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.
EasyBib - Automatic works cited and bibliography formatting for MLA, APA and Chicago/Turabian citation styles.
bibme - Reference management software.
Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.
Bibcitation - A free online tool to generate citations, reference lists, and bibliographies. APA, MLA, Chicago, and more.