Tags vs. Categorization
My usage of tags vs. categories is cyclical. Is it easier to provide a tree or breadcrumb structure to find new topics or allow for many to many associations? At the moment, I am using tags again in my email (thanks to Jamie!) vs. moving to folders…the latter seemed too old school.
Tagging also allows me to change what I think of the subject by adding a tag or deleting but not messing up the structure. Kind of like MongoDB vs. SQL.