WP-Lightform is an AJAX / PHP contact form with spam protection, form validation and custom form elements.
This plug-in lists all the plugins you are using. The plugin can inserts a simple html list of your blog plugins into any post/page.
Postlists plugin provides placeholders for dynamic lists of posts you can configure in the admin panel! You can define the placeholders yourself and configure the list that should replace it.
Role Scoper is a comprehensive drop-in replacement for capability enforcement and administration in WordPress. Assign reading, editing or administration roles to users or groups on a page-specific, category-specific or other content-specific basis.
Sensitive Tag Cloud provides a configurable tagcloud that shows tags depending of the current context only.
WP Math Publisher allows you and your visitors to create math equations without LaTEX or MathML.
The User Rank WordPress plugin ranks users based on their total number of comments, posts or a combination of both.