Good article over at Boxes and Arrows illustrating the many levels of IA. This is a somewhat detailed overview of how Information Architecture is used from the top-level (Navigation and tangible user interfaces) to the lower-level or backend (Controlled vocabularies, metadata structure, Content Management).
Illustrations give a conceptual overview of how a well-structured IA can be used "behind-the-scenes" to allow for dynamic content relationships. A solid IA including well-defined metadata (information describing information) and controlled vocabularies can be used to generate dynamic pages that illustrate related items or content. sounds like fun...
Link:
http://www.boxesandarrows.com/archives/building_a_metadatabased_website.php