Don’t know what Microformats are? Go to the Microformats page, and read their wiki.

Now, no current browser supports Microformats, but there are plans to integrate this into Firefox 3. To get Microformats to work on a Mac for now you could use Firefox 2 with the Tails extention. But if you want to use Safari there is this nice CSS stylesheet that will help you discover Microformats from within Safari. The CSS doesn’t help you download the information but it does help you encountering any hidden Microformats.

With this CSS I managed to find quite alot of them at IMDB, Amazon, Plazes and Upcoming.