Zotero is a free citation management tool that can automatically import citations into your personal account, organize sources into folders, and generate bibliographies in a variety of citation styles. It also includes a word processor plugin for formatting footnotes and parenthetical citations.
ZoteroBib is Zotero's quick cite tool.
More sophisticated than EasyBib, RefWorks is a web-based tool that allows you to collect and organize citations, format papers, and create bibliographies. RefWorks allows you to create bibliographies in individual journal styles, as well as Chicago, MLA, and APA.
You may open multiple RefWorks accounts so that you can easily share citations with other students for group projects or lab research.