Selected recent presentations can be found on SlideShare
Some earlier presentations:
Semantic Technology and Ontology
Ontology Summit 2009 - April, 2009
NIST's Semantic Approach to Standards and Interoperability - February, 2004
Smart Grid Interoperability
Interoperability Lessons Learned from the eCommerce, Manufacturing and Business-to-Business Sectors - September, 2008
Manufacturing Interoperability
(under construction)