Creating Restricted/Constrained PowerShell Runspaces

One of the neat parts about PowerShell's Remoting feature is its support for constrained runspaces. "I want admins to be able to remote into this server, but I only want them to be able to run certain commands, and I don't want them running scripts." It's possible - although requires a bit of work to configure.  Here's a great write-up  on the concepts; thanks to  @adamdriscoll  on Twitter for calling this to my attention, and to  @ravikanth  for writing it up!