I run the Pogoplug desktop app on three machines in a few areas, as well as my Android phone. If my phone were to get stolen, or any of those machines, it would be really great if I could remotely sign out all of the sessions that are currently logged in. That way the theives wouldn't have access to my Pogoplug data.

For a good example of this in action, please see how Dropbox and Google (and even Facebook) allow you to sign out all current logins.