In library school, we learn about LC subject headings and other structured, formalized ways of categorizing information. This is important, and no one is arguing that we should give up on subject headings altogether, but I think librarians need to at least understand the way users are organizing their own information. Tagging, exemplified by social bookmarking sites such as del.icio.us, allows users to create their own labels and then compare them to the labels that others have used.
Library school student Kirsten of Into the Stacks has some interesting thoughts about tagging:
When I browse through the bookmarks in my network, I use the tags to help decide whether it’s something in which I’m interested. Since site titles can be misleading or uninformative, and most people do not regularly add user notes for their bookmarks, tags are often the only way I have of judging the usefulness of a site without clicking through.
GrahamLavender.com 
Thanks for the link, Graham. I hope you read the article that inspired that post — the authors did some pretty interesting research into user behavior on del.icio.us.
I’ll admit that I’ve only read the abstract so far (typical grad student habit, right?), but I’m going to take a look at the rest of it now. This is the sort of material I wish we could discuss in school.
Do y’all have some sort of journal club? We just started one this semester, and it’s a good place for this sort of thing.
We don’t, but that’s a great idea. Do you have a webpage for your club, or is there any info online that might help someone who wanted to start a journal club?
The club’s page is here. I’m sure there’s other stuff out there, but it’s my spring break so I’m gonna let you go hunting. ;-)
Excellent, thanks! Enjoy your break.