It would really scratch my itch on ANY system if there's a "Recent Activity" sidebar block, with My Favorites, My Starred Items, or My Tagged Items; along with a Search feature within the items contained within the Recent Activity block. And for goodness sake, allow me the ability to sort and reorder the items in such lists.
Call this a "Personal Parking Lot" if you will -- but I really want a way to organize useful content for later retrieval, and this is how I'd prefer to do it.
Without such a feature, I'm stuck with Firefox Bookmarks or Delicious Bookmarks (via Firefox Toolbar); and I'm really not all too happy with either of those. (I'm open to suggestions!)
Social Networks get cluttered with content quickly, and there's nothing that ticks me off more than "Searching" or paginating back within the system to find an article that I came across only days before. System-Wide Tags don't work; and System-Wide Ratings don't work. It's got to have displayability and searchability within your own personalized tags/ratings/starring.