It also shows the total usage of Windows Server 2008 TS PU CALs (including expired), and the usage of Windows Server 2008 TS PU CALs for a list of specified domains.

The major scenarios addressed by the script includes the following -

1. For a Windows Server 2003 TS, this script helps the administrators tracking the users logged in to a TS in PU licensing mode over a period of time.
2. For a Windows Server 2008 TS or a Windows Server 2008 R2 Remote Desktop Session Host Server (RDSH), this script helps the administrator tracking both valid & expired PU CALs.
3. For a license server running Windows Server 2008 or Windows Server 2008 R2, this script enables administrators to generate PU CAL usage details for a list of specified domains.
4. For a license server running Windows Server 2008 or Windows Server 2008 R2, while generating the PU CAL usage report for a list of specified domains, even if one or more of the domains in the list is unreachable, this script will still report the usage for all the reachable domains.

For more detailed information, download the Per User Report Generation script from here. The batch script to execute the Per User Report Generation script periodically for a Windows Server 2003 TS is available at here.

Source: http://blogs.msdn.com/rds/archive/2009/11/09/per-user-cal-reporting-script.aspx