http://technet.microsoft.com/en-us/s.../bb842062.aspx
Many of these are quite useful, at least for me. As long as you have administrative access to, and a connection to a Windows remote PC, using these tools, you can do just about anything you need to. You don't need to install anything on the target computer to use these.
For example "PSEXEC \\computername cmd" will launch an invisible command prompt on the remote computer, where you run commands from your own computer.
Where I work, I have admin access to at least 100 Windows PCs and have found the sysinternals tools to be very useful for things like installing updates without interrupting the person who is using that computer.