My newest plugin has just been submitted and accepted at WordPress.org. The idea of the plugin took form in talks between me and TDH who is the creator of the Notes Core WordPress theme and the writer of Smashing WordPress: Beyong the blog. The plugin is called Notes PostWidgets and this is the description from the readme file.
Notes PostWidgets is a plugin which adds a custom post type (“Post Widgets”) that you can use to create text widgets with. This way you can use the built in WYSIWYG (What You See Is What You Get) editor to set the mark up on your widgets. You can set a custom CSS class name for each widget for more specific mark up.