Microformats have been around for some time now. We have been using simple hCards and hCalendar markup on some client's sites and on our own. Actually in new projects we are doing it for free as part of our ["Serienmäßig inklusive"] package. We tell our clients so in our offers but to be honest I do not expect anyone to understand what we are talking about at the moment.
The topic tends to be a bit too [theoretic] as long as we do not have any wide-spread browser with native support for microformats (Firefox 3 anyone?). At least I have difficulties explaining non-tech-savvy people what microformats are and why it is a good idea to implement them today.
Tantek Çelic's talk on Microformats at @media 2007 in London showed me some new opportunities that I think would make it easier to explain the topic to others:
1. Automated vCard generation from hCard markup
The guys at Technorati (and possibly others, too) offer a simple but impressive service. By putting a special link next to some hCard markup, website owners can give their users the ability to download a vCard version of that contact information and use it in Outlook, Apple Address Book or whatever app they use.
Just add a link pointing to
http://feeds.technorati.com/..../http://www.your-website.com/page and you are done.
2. Automated iCal generation from hCalendar markup
A similar service exists for hCalendar events. The idea is the same and the URL only slightly different:
http://feeds.technorati.com/..../http://www.your-website.com/page. Users get an iCal file and can put that on their Outlook calendar, Apple's iCal, Mozilla Sunbird and so on.
3. Automated webcal feed generation from hCalendar markup
This one rocks. Imagine a page with a list of events. Using the technique described in  you could easily add a link to an iCal file that users could download and import. But what happens if the event list changes, one event is added, another cancelled? The user needs to check with the page regularly to stay up-to-date. No longer.
The solution is called webcal feeds. Using another service offered by Technorati, users may subscribe to a feed of this list of events which is then periodically updated by their calendaring app. The webcal protocol is currently supported by apps like Apple's iCal and Microsoft Outlook from version 2007 on.
Again, all you have to to is add a link to
webcal://feeds.technorati.com/... and you are done.
Using these three it should be possible to show everyone the potential of microformats.