So, it seems that the makers of endnote have decided that they are screwed.  They are suing the makers of Zotero (which is awesome), and George Mason University is amazingly backing them up, and kicking Thompson-Reuters to the curb by cancelling their university-wide subscription.

Go freedom and openness!

Zotero may not be quite ready for mainstream use yet - but it looks like the most promising path to a better system of shared scholarship.  The goal is for everyone to have a repository of citations embedded in a "web" built by and for the communities that are actually doing the important work.  But you might check it out anyway.

Somewhat ironically, if you don't have a personal or institutional subscription to Nature, I don't think you can read their "defense of Open Standards and Innovation" linked above.  Sorry about that.  Maybe you can get a villainous friend to give you an illegal copy?