Honorable mention:
-Email-to-Speech (talking emails) using Yahoo’s BrowserPlus in the upcoming ZCS v6. It’s manual right now, but the possibilities; like saying the senders name/subject out loud automatically would be impressive…as long as it wasn’t reading a spammer’s offensive subject (maybe use a whitelist).
-Drag n’ Drop upload extension So useful I can’t imaging using Zimbra Desktop without it.
You can find a whole slew of them / see what’s possible over at gallery.zimbra.com
If you find one your organization needs (Alfresco, Xythos, Dimdim ProcessMaker, RPost, etc) I’m sure the Vorari staff would happily install/enable them for you.