Simple 'back' and 'forward' buttons (as in Firefox) would make it so much easier to work on several citations, and maybe notes and documents, at the same time.

I find it annoying that, when I'm working on a citation and just need to check something in another citation or note, I have to perform a search to get back to the original one (if I remember which one it was). A single click on a 'back' button would be so much more practical.