Can I group items only in the Outliner I would like to hide many items in the Outliner by grouping them and then collapsing the group.

I realize the Outliner can display only Groups, but those groups are functional groups that affect the way, for example, animations work.

The kind of groups I'm wanting to create are solely for the purpose of reducing visual clutter in the Outliner and won't effect anything else.

I saw this question was asked before, but none of the answers solved my problem. (How can I organize the outliner with groups?) 

Does anyone know of any solution?
I had a need for something like this sometime back and as far as I know there is no way of doing this in Blender yet.

What I did was create and name some empties and then just parented the objects to it. To reduce clutter, you can keep the empties on a garbage layer and also reduce their size or disable relationship lines. Empties and their relationships to the child objects won't affect anything and you get to toggle the different 'groups' as needed.