I like that there is consistency in naming them when considering the periodic table. However, most people don't know the table well enough to know their atomic number, their classification (noble gas, halogen, etc.) nor would there be any connection between name and purpose. Rather you must know the meta-information about the element to know the purpose which makes this a well-suited convention for chemists but few others.
Usually the hostname should be disconnected from the machine's purpose. Instead, use a generic name and then use aliases (either cnames or additional A records) for mapping services to the machine.
I don't think nnutter meant naming machines by their purpose like "mail.localdomain", "www.localdomain", etc. Rather, for example, I once named a QA build-testing machine "yaeger" after the test pilot that broke the sound barrier. Hostnames whose namesake has similar traits (even vaguely) to the machine's purpose can help you remember which machine performs what task on your network, or recall what a machine's purpose is by it's hostname. Careful selection of such names provides these benefits without causing any more problems when you move a service to another machine than using any other naming scheme.
