For busy websites, using a CDN (Content Delivery Network) to transfer static content such as images, javascripts, stylesheets, Flash etc. is highly recommended (as listed in Yahoo!’s Best Practices for Speeding Up Your Web Site) as it reduces server load and bandwidth thus improves stability and availability.
There’s plenty os commercial CDN’s like Akamai, Limelight, FileCloud, Amazon S3… and as far as I know just an exception, the free P2P-based CoralCDN allows us to take full advantage of a powereful CDN without spending a dime.
How to use it? Well, basically, just append .nyud.net to the hostname of any URL, and that URL will be handled by Coral – simple.
Examples:
https://garridodiaz.com.nyud.net https://garridodiaz.com.nyud.net/wp-content/themes/neo-fluid-blue/style.css http://www.coralcdn.org.nyud.net/imgs/logo.jpg
The service works really good as far as I could try, but it’s slow, nothing to compare to Amazon S3 and can help us to prevent hotlinking other sites.
Also we can find a WordPress plugin Free CDN that makes things easier in WP.
Remember another interesting service to cache your images rir.li.