The first 2 structures that this has been applied to are vcard & icalendar - the microformat equivalents are hcard and hcalendar. Formats also exist for reviews, resumes, relationships etc.
Microformats are a way of taking information that already exists and adding structure to allow the information to be parsed.
So whats the point? Imagine google indexing the site not just for plain text for for specific event information, being able to click on contact information or an event and adding it in your address book or calendar, clicking on an address and seeing it's location (and getting directions) from google maps?
The great thing is that it's not a lot of work to put things into this format. This is actually encapsulated in the official definition of microformats:
Designed for humans first and machines second, microformats are a set of simple, open data formats built upon existing and widely adopted standards.
I was able to convert the address in footer of the designIT site to a vcard with some simple re-formating.
<span class="fn org">designIT</span>
<span class="extended-address">10.01</span> <span class="street-address">365 Little Collins Street</span>
<span class="locality">Melbourne</span>, <span class="region">Victoria</span>
<span class="country-name">Australia</span> <span class="postal-code">3000</span>
P <span class="tel">
<span class="value">+61 3 9913 0044</span>
<a class="email" href="mailto:email@example.com">firstname.lastname@example.org</a>
The eZ publish Training & Certification in Sydney, Australia 4 - 6 December 2006 post was formatted using the hcalendar format and utilises embedded hcard information for the location.
Here is some more reading:
- The home of all microformat information.
- technorati have a microformat indexing & search service
- Tails is a firefox extension that parses microformats in pages on the fly and is expandable via scripts
- How microformats affect search engine optimization