Zotero | An Excellent Easy Free Bibliography and Citation Manager

Zotero | Home: "Zotero [zoh-TAIR-oh] is a free, easy-to-use Firefox extension to help you collect, manage, and cite your research sources. It lives right where you do your work—in the web browser itself.
Zotero screencast
Features

* Automatically capture citations
* Remotely back up and sync your library
* Store PDFs, images, and web pages
* Cite from within Word and OpenOffice
* Take rich-text notes in any language
* Wide variety of import/export options
* Free, open source, and extensible
* Collaborate with group libraries

* Organize with collections and tags
* Access your library from anywhere
* Automatically grab metadata for PDFs
* Use thousands of bibliographic styles
* Instantly search your PDFs and notes
* Advanced search and data mining tools
* Interface available in over 30 languages
* Recommendation engine and RSS feeds"