advanced tag search
Since a thought can have multiple tags, let's have a more advanced tag search as follows:-
Show a list of tags and when you click on a tag, a second list of tags appear which are the tags that are paired with the first one; click on one of these and a third list appears with all the tags that are paired with both these selected tags; and again repeat with these list until there are no more paired tags. As you are selecting these pairing of tags, the report tab (some appropriate place) show a list of thoughts that have all of the selected paired tags. This provides a more visual and faster way of selecting multiple tags and more compact and less cluttered results display.
To best illustrate what I mean see http://johnvey.com/features/deliciousdirector/demo.html.
-
kit commented
Since parent thoughts are interchangeable with tags, the list of tags could include any thought that is a parent and in the second list is a list of child thoughts of the selected parent thought. When you click on a child thought, the third list is a list of child thoughts of the selected (second list) thought. I hope this is clear.