acts as taggable worth using?

This should help answer your question:

http://www.flickr.com/groups/central/discuss/2730/

The fundamental point is that you let your users do the organization
and categorization of the content. Usually it's them tagging content
they themselves have created, but it's not unheard of to allow users to
tag content created by others (such as visitors tagging content /you/
create).