http:/ / www.archive.org/ web/ freecache.php
Freecache from the Internet Archive aims to bring easy to use distributed web caching to everyone. If you've a file that you think will be popular, but far too popular for your isp's bandwidth limits, you can just serve it as http://freecache.org/http://your.site/yourfile instead of the traditional http://your.site/yourfile and Freecache will do all the heavy lifting for you. Plus your users get the advantage of swiftly pulling the file from a nearby cache rather than it creeping off your overloaded webserver.
