Updating Farm Administrators Group in SharePoint with Powershell

Below is a simple PowerShell script you can use to add a user or AD group to the Farm Administrators group in Central Administration. It's actually the same script you'd use to add a user into ANY SharePoint group, so it's helpful for more than just this one purpose:

[void][System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SharePoint")

$CAPortNum = "12345"

$userOrGroup = "philsdevdomain\phil"

$site = new-Object Microsoft.SharePoint.SPSite("http://"+$env:COMPUTERNAME+":"+$CAPortNum)

$web = $site.RootWeb

$farmadmins = $web.SiteGroups["Farm Administrators"]

$farmadmins.AddUser($userOrGroup,"","","")

$web.Dispose()

$site.Dispose()