Reference managing tools can help researchers organize research materials and improve efficiency. Mendeley is one such free tool that allows users to build a local reference database, search for papers online, share papers and collaborate with other users. It automatically extracts metadata from PDFs, allows annotations, and has a Word plugin for citations. Over 30,000 users have added over 3 million references to their Mendeley databases. While no tool is perfect for all, Mendeley provides a good balance of features and usability to help researchers manage references and collaborate more effectively.