Something that I have always thought could improve Zotero is the functionality when you are clicking on a doi hyperlink inside an article's pdf.

If Zotero could somehow check if the paper being linked already exists within your database (some sort of search and compare with the clicked hpyerlink). Then if the link does correspond to an item your database, instead of opening the hyperlink it could just bring up the paper in your database!

I think this would be hugely beneficial and would also help to cut down on duplicate entries (although that isn't really the point).

I would be very curious to hear if anyone else thinks this would be useful or has an idea for how it could be implemented.