BloxPress is a theme and template engine for WordPress that allows viewers of your blog to configure their own widget modules in your sidebars. If Bill likes to view the last 10 comments and Jane likes to see your latest Flickr uploads, they can have both at once with their own configuration.
Individual user preferences are stored in a cookie and anyone can create their own “blocks” for the system. Check out the demo to see the system in action.
It’s too bad the blocks do not seem to interoperate with any other widget definition format. I’m glad Spaces will be adding Microsoft Gadgets to its sidebar, increasing the usefulness of the format whether it’s on a personal start page, desktop sidebar, or blog sidebar.