I came across this simple trick purely by accident when setting up lighting for a room full of furniture. I ended up supplying indirect/direct lighting for an entire scene with a single light and a plane. The great part of this technique is that it renders really fast.
For a test of how this works, setup a standard scene with a V-Ray Plane that has a checker diffuse. Add a teapot to the center of the scene, with any material. Lastly, add a standard Target Spot above the scene. Crank up the intensity multiplier to 3.0. The scene should look a little like this:
