Second, you need a special web server/apache module/whatever. It should be able to communicate with that little special DNS server, post stuff to other servers, accept stuff from other servers, and time out stuff.

How it works? Suppose we have the distcache.example.com domain. Step zero: everybody wishing to participate registers at our special DNS server as distcache.example.com. Now I want to post a picture of my aunt Jemima to my precious little blog. I'm running that little apache module. First I generate a UUID for that picture, say 12345-67-8. Next, I instruct my apache module to serve the picture whenever a request for http://12345-67-8.distcache.example.com/ is coming. Next, I tell the special DNS server that I'm 12345-67-8.distcache.example.com and wait for requests.

When a request comes, the web server just serves it out. Also, it asks our DNS server for a distcache.example.com's IP. The DNS server just spews out IP in a round-robin fashion, so I get some random participant's IP. I post my picture to that participant's web server. The participant's web server accepts the picture and registers itself as 12345-67-8.distcache.example.com. The next request for aunt Jemima's picture will come to that host, not to mine. That host of course will do the same: post the picture to someone else, etc.

I know I'm stupid. Of course it will never work reliably.

Hell, I forgot how to write in English.