Trick Windows clients with a different Windows Domain Name

At one time, I seemed to remember hearing about a method to mask the real Active Directory domain name to your windows clients.  For example, let's say your company name is ACME and that's your Active Directory domain name.  ACME is purchased by CONTOSO, and a project is quickly pulled together to do something about the old Active Directory domain mame of ACME.  I thought I read where someone had devised a way to make it so that the clients would "think" the domain name was CONTOSO, when it was actually still ACME.  I could see this being useful as an interim solution while a domain migration strategy and project is put together.  Anyone heard of this?