The Tag, You're It panel discussion from SXSW Interactive has some good information on tagging. There are four panelists, including Thomas Vander Wal, and it might be nice to see the slides, but C'est la vie.
Services such as Delicious, Flickr, and others allow users to tag various kinds of content. Some people use the tags for personal information management -- making things easier to find -- and others use tag to discover certain kinds of content -- such as pictures of puppies. But are people tagging the content with that use in mind? For use by others? Or just for personal use. This panel will consider trends in tagging, as well as the _possible_ social value it can bring. (This panel will not look at how cool and important folksonomies are; it will look at how people actually behave inside them.