From Svendsen Tech Powershell Wiki
Quest ActiveRoles is a collection of very useful PowerShell cmdlets for Active Directory, offered for free by Quest Software.
The Quest Activeroles cmdlets now (February 2012) require PowerShell version 2. They also work against 2003 R2 domain controllers without Active Directory Web Services.
To add the AD management snap-in manually, you can use the following command, so you don't have to start the specific shell/host environment they provide:
See Getting computer names from AD using Powershell for an example with the Get-QADComputer cmdlet or Getting usernames from Active Directory with PowerShell for Get-QADUser.