Logout statement??

I am using an openurl with form-perma to avoid showing the menu structure and the global search field. It works great except there is no way for the user to log out.

Can a deluge statement be added that will log a user out?

An added ability to automatically logout after a set number of minutes of no activity would close some security holes. Currently a user might login to an application on a public computer and walk away, leaving the application exposed for hours or perhaps days.