If you have control over your DNS you can setup 'wildcard hosting', which means you can have a webserver accept connections for any given subdomain. This can be enormously useful for community websites, or other hosting purposes. One popular site which uses this technique is Livejournal, another less obvious one is Slashdot.org. The end goal of using wildcard hosting is that you'll be able to setup a webserver for a domain, such as example.com which will serve requests for any subdomain. For example the following would all be valid hosts: * foo.example.com * private.example.com * cvs.example.com *...