"This utility allows you to define groups of lights - for easy management. You can then turn all the lights in the group On/Off and Hide/Unhide them. It is useful for task such as having the same scene with day/night light schemes, or when you have to dead with an important amount of lights.
This script is an update of Light Grouper, you can find on scriptspot. It now supports vrayShadows, and Vrayshadowmaps"