http://go.vertigion.com/PowerShell-SearchAcrossMultipleDomainsInForest

SearchAcrossMultipleDomainsInForest.FindAll.ps1

try {
  foreach ($res in $Search.FindAll())
	{
		$User = $res.GetDirectoryEntry()
		
		$NewObject = New-Object PSObject
		Add-Member -InputObject $NewObject NoteProperty 'DistinguishedName' $User.DistinguishedName
		Add-Member -InputObject $NewObject NoteProperty 'SamAccountName' $User.SamAccountName
		$OutputList += $NewObject
	}
} catch { if ($error[0] -ne $null) {Write-Debug $error[0]} }
$OutputList