] My experience with folksonomies, ad hoc user-generated
] tags for classifying web content, is that they help you
] understand what the individual who created the tag thinks
] of the content he or she is classifying. By themselves,
] the tags tend to be too ambiguous for inferring too much
] about the web content they are used to classify. However,
] what may be quite useful is seeing who is tagging the
] same web content you are tagging; that way you know you
] may have something real in common.

The Community Engine Blog: Folksonomy %u2014 One Man%u2019s Experiment