Resetting session of particular user

I am accomplishing this by storing the session_id in the user model. When a user logs in I update the user model with the current session_id. Then I have a before filter in the application.rb that checks that the session_id stored in the user model matches the current session_id. If it does not, the user gets logged out and a friendly error message telling them they logged in somewhere else. The current session id can be accessed with session.session_id