TextCite

TextCite is a program for organizing and commenting textual citations from texts (books, articles, or other published works) for use in producing scientific or academic publications.

You can organize by publication, author, category, or outline.
It works with bibliographic management programs like Citation, EndNote, RefWorks, and BibTeX, providing important text/citation management capabilities that these programs lack, while still allowing for rapid footnote and bibliography generation by means of your favorite bibliography manager. It also exports to PDF and Word (RTF).