Well actually it's more of a simple trick really. This is how you do it:
1. Create and empty scene(workspace)
2. Add a plane that covers pretty much your whole viewing area when you will render it and make it white. Set diffuse to 100.00.
3. Then add a few simple lights here and there and give all of them physics abilities. Also make sure you give each light a different height, some of them need to hang quite high up.
4. Fire up the physics engine and voila, now you should see pretty much all you see in my video.
I do suggest however you reduce the size of each light to as small as possible, that way it looks better.
I hope you find it helpful, I myself will be experimenting with this some more and see what else I can use it for.
