At 11PM on Friday night, RyanKing and KevinMarks presented about microformats. For more info, take a look at http://microformats.org, especially http://microformats.org/wiki/introduction.

Presentation on FlockDemo also mentioned intentional compatibility with Microformats.

The audio for the talk is available [http://blog.labnotes.org/2005/08/22/podcast-ryan-king-on-microformats-barcamp-05/ here]