Scripts n Styles free WordPress plugin

This plugin allows Admin users the ability to add custom CSS and JavaScript directly into individual Post, Pages or any other registered custom post types. You can also add classes to the body tag and the post container. There is a Global settings page for which you can write Scripts n Styles for the entire blog. Admin’s can also add classes to the TinyMCE “Formats” dropdown which users can use to style posts and pages directly. As of Scripts n Styles 3+ styles are reflected in the post editor. Because only well trusted users should ever be allowed to insert JavaScript directly into the pages of your site, this plugin restricts usage to admin type users. Admin’s have access to even more sensitive areas by definition, so that should be relatively safe