I normally divide it up a little different.
1. The things I want to save for possible use later. 2. The things I need for something specific but only once. 3. The things that I want to read later. 4. The things that I use now and then or often but can never remember the url for.
The last of the four to me is the one most often overlooked and is why I still haven't found a tool I like.
Things that fall into that category is.
My netbank, internal links, insurance site, things I am a member of, online tools, asset libraries that I use often etc.
The best analogy I have been able to come up with so far is a desktop/launchpad for the browser and it might be exactly that way of thinking about bookmarks that will make someone come up with a good enough solution one day.