Custom Post Widget allows you to display the content of a custom post type called Content Block in a sidebar widget.
Gecka Submenu allows you to put menus or potions of menus anywhere in your site: sidebar, templates or page contents.
Shuffle modifies and improves your Media Library in a number of ways.
All in One Webmaster has options to add Google, Bing, Alexa, Blog Catalog, Yahoo’s Webmaster and Analytics code (meta tags).
AVH Extended Categories gives you two widgets for displaying categories. One is a replacement of the default category widget to allow for greater customization. The second is a Top Categories widget.
SyntaxHighlighter Evolved allows you to easily post syntax-highlighted code to your site without having to escape the code or anything. As seen on WordPress.com.
WP Social Blogroll provides a sidebar widget and a template tag that adds an enhanced blogroll to your sidebar. It checks on all your linked sites for the most recent updates.