My Category Order allows you to set the order in which categories will appear in the sidebar.
My Category Order allows you to set the order in which categories will appear in the sidebar. Uses a drag and drop interface for ordering. Adds a widget with additional options for easy installation on widgetized themes.
My Category Order has been out since WP 1.5 or 2.0 (2006) and it's been a struggle to keep it working smoothly. The taxonomy.php hack was hideous and a filter finally got added that let me avoid this. No more visiting the My Category Order page after every single WordPress update!
As of version 2.8.6 of the plugin I'm breaking backwards compatibility to add new features like a multiple widget instances. Keep using version 2.8.3 if you are not on WP 2.8 yet.