Mozilla Labs launched a pretty neat extension called Operator which reads a sites Microformats, such as hCalendar and adds menus to use that data in other sites and local applications.
Basically, say you have a calendar of events on your site. If you markup your HTML following the hCalendar Microformat, this Firefox extension can read your event and can easily add the event to your calendar of choice. There are several other Microformats supported as well.
While right now the Operator extension is sluggish, it’s use of Microformats is very exciting. This is truly moving the web forward! We’ve used it a little on éS Footwear and I can’t wait to pay closer attention for the upcoming etnies relaunch.