In the past I have looked into technologies promising to lead us to the promised land of Semantic Web. RDF and OWL are a couple of examples. Though they are powerful and capable formats they are a bit of a chore to come up to speed on and not to easy to implement into something usable and scalable. You see folks using them to solve specific problems in niche and primarily vertical scopes but you don’t seem to see signs of any widespread adoption by the masses. Then comes along Microformates. From what I’ve read, XFN is what evolved into the first microformat. Today there are many more useful formats. MF’s are sort of a grassroots effort to stitch semantics into the content being published to the web by those who do much of the publishing. Some of the microfomat goals are to solve specific real world problems, start as simple as possible, and reuse existing, widely adopted standards. These concepts make microformats very easy to pick up and start utilizing immediately. Links I found useful

• Tantek Çelik Hcard creator
• Firefox Operator add-on (leader of the pack for the FF microformat add-ons)
• A PHP microformat lib
• A Ruby microformat lib
• Get your mf data out to the world
• some sites utilizing mf’s (hint: install Operator first)
  • cork’d
  • Upcoming
  • Eventful
  • Tech.Yahoo