Currently, the most popular use of microformats is to export them to their native formats, (hCards -> vCards and hCalendar -> iCal), but there’s really should be more utility for microformats than that.
Here’s one neat thing you can do - I created a little application that will allow you plot and describe places on a Yahoo Map easily using the hreview and geo microformats. Generate the HTML from the application, slap it on your own blog (with your own Yahoo! Application ID of course), and away you go. To modify the web plots, just revise your HTML and reload.
Check it out and let me know what you think. I used it to plot some places around my neighborhood where I like to eat.