I have several add-ons installed but the only one I actually care about is TagSifter. It isn't available for 3.5 yet, but it's the only way of managing bookmark

I have several add-ons installed but the only one I actually care about is TagSifter. It isn't available for 3.5 yet, but it's the only way of managing bookmarks I've found that makes any sense to me. It combines the ideas of folders and tags in a very nice way.