You can either hit the viewer directly using http://www.xformats.org/MicroViewer and whack in an url or you can append the URL to the query string.
Why is Jason doing this? In his words:
"It's also a small piece of a larger project I'm working on, but I wanted to throw it out there because I see a lot of misunderstanding right now about the potential of microformats. Although I think it's very cool that search engines like Technorati are beginning to understand and aggregate microformatted content, that's only half the equation. The other half is that we need to allow PEOPLE to use microcontent as well. "
He then goes on to make a suggestion for the Microsoft Office team:
"Oh and by the way, listen up Microsoft: we need an editor for this stuff. If you really want to leapfrog the competition, do us all a favor and build Live Clipboard and microformat support into the next version of Word and Outlook."