Mainstream Microformats

From the yahoo local blog

Starting today, we’re happy to announce Yahoo! Local fully supports the hCalendar, hCard, and hReview microformats on almost all business listings, search results, events, and reviews. There are a few reasons behind this change, which for now, will be transparent to almost everyone.

In less-techy terms, “microformats” are an open standard for structuring web page content in a meaningful and reusable way. At Yahoo, we’ve been big microformat fans — Yahoo! Tech uses the hReview microformat for all product reviews, Flickr supports XFN and hCard on all profile pages, and our own Upcoming.org was the first big hCalendar supporter.

This sounds like a big step forward for the "grass-roots semantic web". A bit more about this here, although I'm still not sure how exactly the microformat support looks like...