Who can create a shared folder in a Server 2003 domain?

Hi, Im a college IT student and our class is learning Windows Server 2003.

We are having trouble figuring out which users are authorized to create shared folders on a Server 2003 R2 Domain. It seems that the Domain Admins can, but the more limited Domain Users cannot. What is the lowest level of group membership that is required to share a folder?

Or is there some default domain policy setting that would prevent a limited domain user from sharing a folder in the domain from a Windows XP computer?

Thanks, Chris