This is a new logic script oriented toward toggling something on and off, whether for a single thing in the scene or for each individual visitor to (or object in) your scene. You could use this to toggle the turning on and off of a single light using a sliding door script in an object with an attached light and a trigger volume on a light switch to trigger the on/off toggling behavior.
You could also use this to toggle on and off some state that is specific to your visitors.
This script represents the version 3 emphasis on increase game-play interactivity through the use of memory for scenes and players. Expect more memory and logic scripts very soon.