Describing itself as the iTunes of reference management, Mendeley is a free research management tool for desktop and the Web. In fact it has created that much of a stir that the Guardian have documented its existence.
Working along the same lines as similar free reference management tools, CiteuLike, Connotea and Zotero, Mendeley lets you explore research trends and connect to other academics in your discipline.
Just like its contemporaries, it comes fitted with everything the modern researcher would want in the wonderful world of Web 2.0. You can find new research, collaborate with other researchers who share your interests, sort and organise your own research library, and much more. With a quick download you can sync your references across more than one PC, and that's where there's a difference between that and others like Connotea and Citeulike, which are totally Web-based. You can import and export from EndNote and easily add papers found in a number of popular services.
Just glancing at some of the other capabilities of Mendeley are enough to entice you to try it out.
Generate Bibliographies in Word and OpenOffice
Gather papers from everywhere
Build your network of fellow researchers
Explore research trends and statistics
If you want to know more, visit the Mendeley site or read The Guardian article here.