Who is Logged on at that Computer?

A quite useful script:

' WhoLogon.vbs
' Sample VBScript to discover which user is logged on
' Author Guy Thomas http://computerperformance.co.uk/
' Version 1.2 - December 2005
' --------------------------------------------------------------'
Option Explicit
Dim objWMIService, objComputer, colComputer, strComputer

strComputer = "."
Set objWMIService = GetObject("winmgmts:" _
& "{impersonationLevel=impersonate}!\\" _
& strComputer & "\root\cimv2")
Set colComputer = objWMIService.ExecQuery _
("Select * from Win32_ComputerSystem")

For Each objComputer in colComputer
Wscript.Echo objComputer.UserName & " is logged on"
Next

' End of Sample Script. Who is logged on?