"Tagging works because it strikes a balance between the individual and social. It serves the individual motive of remembering, and forms a ad-hoc social groups around it."
"Tagging in and of its self is a helpful step up from no tagging, but is no where near as beneficial as opening the tagging to all. Folksonomy tagging can provide connections across cultures and disciplines (...)"
"My guess is that federation across tag spaces will be accomplished by aggregators and search engines. When the subject is avian flu, they'll enable you to compare the resources cited by nonspecialists with those cited by various kinds of specialists (...
General Overview of tagging and folksonomies. Difference between controlled vocabularies, author and user tagging. Advantages and shortcomings of folksonomies