I'm using Radio UserLand to publish several Web sites: Workbench, Orlando Vacationer, and the Bizarro-world news site Drudge Retort. The latter two sites use Radio's categorization feature -- posts sent to Orlando and Drudge categories are upstreamed to their destination, the former as rendered HTML files and the latter as RSS feeds.
This system works pretty well, but one drawback is that posts sometimes end up in the wrong place, as a few did this morning. I'm beta-testing the UserLand editor SmartManila and have found a bug that causes edited posts to rejoin Radio's Home Page category when they shouldn't.
I've been in discussions with UserLand programmers to improve Radio's ability to support multiple sites. If anyone else is using this feature, now's a good time for us to work together.