Mozilla just released Operator, a very promising microformat detection extension for Firefox that demonstrates the usefulness of semantic information on the Web, in real world scenarios.

In creating Operator [...] goals were to create something that was useful to microformat developers as well as users looking to explore microformats. As such, the Operator Toolbar can be displayed in two modes: Microformats mode and Actions mode.

If you’ve not heard of Microformats yet: Those are simple markup structures that allow expression of semantics in an (X)HTML web page, making it easier to read for machines and easier to built for authors because of the adaption to standards.