The ability to manage a vmware instance from the command line can be critical when the GUI or webpage (since VMWare has a built-in web server so you can manage some of your virtual machines) won't work. In this case the following two commands helped me on Windows XP:
C:\> cd "c:\Program Files\VMware\Vmware Server" C:\Program Files\VMware\Vmware Server> vmrun.exe -h "https://localhost:8333/sdk" -P 8333 -T server -u TJ -p PASSWORD stop "[standard] Ubuntu8/Ubuntu.vmx"
This allowed me to user my username (TJ) to shutdown the system using my local (domain) password.
Additional information on the command line switches is also available at http://itknowledgeexchange.techtarget.com/virtualization-pro/starting-a-vmware-server-virtual-machine-with-vmrun
Additional information can be found in the documents at http://www.vmware.com/pdf/vix160_vmrun_command.pdf or at http://www.vmware.com/products/beta/ws/vmrunCommand.pdf