Expires Headers Pro
YSlow and Pagespeed look at Expires Headers when evaluating your site. This plugin allows an administrator to set global Expires, Cache-Control and Pragma headers, as well as individual settings (inclusive or exclusive) for particular menu items.
Speed up your site by following the rules! Set short time-spans for pages that change frequently, and longer time-spans for pages that don't.
Note: Expires Headers cannot alter the expires headers for content that was not processed through the Joomla framework. This includes CSS files, Images, Favicon files and others. These files can be addressed using htaccess rules. Visit the website link for more information and an example.