From How to Shoot Video that Doesn’t Suck, Page 127:
Some videos take place in an ethereal neverland called “limbo”—a seamless, glowing, solid color wash. Frequently black or white, limbo backgrounds are cheap to shoot and they totally focus your attention on the people in front of them.
In this great looking trailer for a film/book package called “The Wisdom Book” by photographer Andrew Zuckerman, the limbo was created in-camera: Zuckerman hung a seamless white background behind his subjects to stay beautifully focused on their faces and words.
You can do the same by hanging a nine-foot roll of white paper (easier to get than you think—just Google “nine foot rolls of paper”) behind your talent, with the paper rolled out along the floor to the camera. Put your actors on the paper.
If you keep your shot inside the paper’s edges and light it so there are no bold shadows, you won’t see anything behind the actors. They’ll be floating in white.