My favorite is the command .cmdtree <file> (undocumented, but referenced in previous release notes). This can assist in bringing up another window (that can be docked) to display helpful or commonly used commands. This can help make the user much more productive using the tool.
Initially talked about here, with an example for the <file> parameter:
http://blogs.msdn.com/debuggingtoolbox/archive/2008/09/17/special-command-execute-commands-from-a-customized-user-interface-with-cmdtree.aspx
Example:
alt text http://blogs.msdn.com/photos/debuggingtoolbox/images/8954736/original.aspx