I have recently switched to Zotero to manage my bibliography and associated notes in addition to the well established Endnote. I think Zotero has the ability to become a more useful tool. Its main benefits are;

  1. its free
  2. it can collect references online from journal sites (jstor)
  3. it works in Firefox and works on all platforms
  4. its free
  5. you can assign tags and search all your notes using those tags
  6. it syncs with all your computers so they are all up to date
  7. and its free!
this is what they say…

Zotero is an easy-to-use yet powerful research tool that helps you gather, organize, and analyze sources (citations, full texts, web pages, images, and other objects), and lets you share the results of your research in a variety of ways. An extension to the popular open-source web browser Firefox, Zotero includes the best parts of older reference manager software (like EndNote)—the ability to store author, title, and publication fields and to export that information as formatted references—and the best parts of modern software and web applications (like iTunes and del.icio.us), such as the ability to interact, tag, and search in advanced ways. Zotero integrates tightly with online resources; it can sense when users are viewing a book, article, or other object on the web, and—on many major research and library sites—find and automatically save the full reference information for the item in the correct fields. Since it lives in the web browser, it can effortlessly transmit information to, and receive information from, other web services and applications; since it runs on one’s personal computer, it can also communicate with software running there (such as Microsoft Word). And it can be used offline as well (e.g., on a plane, in an archive without WiFi).

www.zotero.org