Zotero

Zotero is a very slick, Firefox-integrated utility for capturing full-text or citation information from electronic resources. Roy Rosenzweig provides a nice overview from Academic Commons:

....Zotero is a free, easy-to-use research tool that helps you gather and organize resources (whether bibliography or the full text of articles), and then lets you to annotate, organize and share the results of your research. It includes the best parts of older reference manager software such as EndNote (like the ability to store full reference information in author, title and publication fields and to export that as formatted references) and the best parts of modern software such as del.icio.us or iTunes (like the ability to sort, tag and search in advanced ways). Using its unique ability to sense when you are viewing a book, article or other resource on the web, Zotero will--on many major research sites--find and automatically save the full reference information for you in the correct fields....