CiteULike is a free web-based service that you can use to manage and discover scholarly references, from a select set of scholarly electronic databases and journals. If you find an article supported by CiteULike, you simply click a button and it is added to your library. CiteULike automatically extracts bibliographic information from the article, and you can add additional personal tags. In addition, CiteULike allows you to share your library with others. You can import preexisting citations from BibTex into CiteULike, and export bibliographic information to BibTex, RIS, and Endnote.