ademonicbaby said:
While they do have DNS, do they allow you to use your own nameservers? If so, then the answer is yes, they can be used as a TLD (providing the cp software you use to add the domain is nice enough to let you use such a domain, because it is not, in fact, a TLD. A TLD would be so-and-so.whatever [hence the term Top Level Domain, or TLD]). If not, whether or not they allow custom DNS has no weight in a shared-hosting environment. If you had a dedicated IP for your site, it'd be a different story. But since most (modern) shared hosting environments use Name-Based Virtual Hosting (the method in which the webserver maps the domain/subdomain name to the actual file-system in order to serve request pages), you're quite out of luck. However, you can check into
http://eu.org as they allow custom nameservers. The eu.org requirements are somewhat hard to abide by, and you can find more information on the site.
Cheers,
devHead