I’ve been using Coral for a while now I still love this project. It helps websites mirror their content by sharing bandwidth across a global network…for free 
It makes a big difference for sites that produce content, but dont have to the pipe to serve it up (and can’t afford the commercial services).
I was checking out its official wiki today and I came across this neat technique to seamlessly integrate Coral using Apache mod_rewrite on the response only. I’m not getting quite enough bandwidth yet to need to do this myself, but its a great idea for a small site that needs to save some bits 
Coral Distribution Network Wiki – Main.Servers
One upside of using rewrite links like this is that a server can still see each request in its webserver logs. Of course, the server will see receive an HTTP request per link; however, the upstream bandwidth will only be tiny HTTP redirects, not actual files.
