Not new, but new to me.
If you use CiteULike or Connotea and do research on PubMed, you may find this Firefox Greasemonkey User Script handy.
What is Pubmed2Connotea / Pubmed2CiteULike and how can I use it ?
Connotea or/and CiteULike are a free online reference management service. It allows you to save links to all your favourite articles, references, websites and other online resources with one click. Connotea is also a social bookmarking tool, so you can view other people’s collections to discover new, interesting content. Pubmed2connotea/Pubmed2CiteULike is a Greasemonkey user script which alters the content web page when browsing your bibliography on NCBI pubmed by inserting a hyperlink. This new link adds a new bookmark into connotea with the current selected paper.