From the Equinox site:
It is so beloved because it targets every major muscle in the body — especially the ones we tend to overuse sitting at a desk or a computer all day — and it takes less than 5 minute to complete. Since it’s a dynamic stretch with static components, it can be used as part of your dynamic warm up, to prep your body for your workout, or at the end of a session.
This combination of movement and static positions challenges the central nervous system, forging the connection between the body and the brain that is so crucial to an effective session. When the connection is made, muscles fire properly, so you make the most of every movement and are much less likely to get injured. Plus, this synchronization of movement increases your range of motion, so each exercise can be completed thoroughly.
You can see a slide show of the stretch here.
You can view a PDF of the simple instructions here.
I found the stretch at this site here.
If you Google "World's Greatest Stretch" you will find videos and explanations of different variations of the stretch, the site I linked to has more positions embedded in it. There is no video yet, even though they say to view the video on their site.