A brilliant tip on how to mash up CiteULike and BibDesk (two of my favorite tools). It helps that my article-search workflow is identical to the author’s. If you browse and post to CiteULike, this is a great way to bring those articles into BibDesk.
Academic Productivity » CiteULike + BibDesk: Sync your references and live smarter
Andrew Dawes 
http://jabref.sourceforge.net/ is free software 🙂