WordPress Plugin of the week is Far Future Expiry Header.
What is it?
This plugin will add a far future expiry header for various file types to improve page load speed of your site.
Why do you need it?
In simple terms this plugin allows you to add “Expires” headers for certain file types. Expires headers tell the browser when to request or re-request a file. Most of the time these are left unset on a website, so the files get requested fresh each time the visitor visits your website. If you set the Expire Headers for a time period, the file will be requested locally from a returning visitors machine rather than fresh which will significantly decrease page load speed for returning visitors.
How much does it cost?
Far Future Expiry Header is free!