If you grant a Domain User the Add Workstations To Domain right ( User Manager for Domains / Policies / User Rights or NTRIGHTS), they will be able to remotley add a workstation or server (non-domain controller) computer accounts to a domain using the Add To Domain command in Server Manager from the Resource Kit and remotely remove computer accounts that they created.
This right will also allow them to join a domain from a Windows NT client using Control Panel / Network and entering their username and password. If this causes:
Unable to add or change accounts on the domain. The account information entered does not grant sufficient privilege to create or change accounts. the account has already been added by someone else and must be removed by them before the users can join the domain.