Sub domain creation by site administrators

Is it possible to allow site administrators to create their own sub domain rather than having us the ISP do it for them?

i.e. can this feature be enabled for site admins somewhere?

Thanks in advance.

Sure, a virtual Server administrator can create a Sub-Server, which can be a full domain, or a sub-domain.

You can see what a given admin is allowed to do by going into Administration Options -> Edit Owner Limits.