Yahoo! Support for Microformats
Yahoo! Local fully supports the hCalendar, hCard, and hReview microformats on almost all business listings, search results, events, and reviews.
Microformats are simple, open data formats for structuring microcontent like events (hCalendar), contacts (hCard), and product reviews (hReview) for meaningful encapsulation and reusability.
It's a bore/chore to copy event details, piece-by-piece, from a web page to the fields in one's calendar. Why not wrap up the details of an event into a format that can be understood by calendars, event aggregators, and other applications? Same for contacts, etc.
Some Microformat support also exists in Yahoo-acquired web 2.0 heavy-hitters, Upcoming and Flickr.
Tantek Çelik has been steadily building steam for Microformats for awhile. Their success almost demands ubiquity. I'm glad to finally see strong adoption; CriticalMass/TippingPoint will be sufficiently semantically efficiently exciting.