Something of a virtuoso performance from Andy Powell: Does Metadata Matter?.
This a 30 minute slidecast (using 130 slides), based on a seminar I gave to Eduserv staff yesterday lunchtime. It tries to cover a broad sweep of history from library cataloguing, thru the Dublin Core, Web search engines, IEEE LOM, the Semantic Web, arXiv, institutional repositories and more. [eFoundations: Does metadata matter?]
This stands up well just as a powerpoint presentation. The rapid-fire slide style (echoes of Dick Hardt) works very well.
If you listen to the presentation (click the arrow in the middle) you get more information but it moves more slowly.
Following the discussion of cataloging in the library community Andy says: "metadata tends to get more complicated the longer you think about it". I wonder what he can mean ;-)