Social psychology is so much fun.

My friends and I did something like this once!

We got stranded at my dad's office for 2 hours while he worked, and hi jacked an elevator.
After trying a dancing elevator (door opens, the 4 of us inside are dancing wildly) for a few minutes, we got bored and tried to see if we could pull off stuff like this.

We would all stand in one elevator and then as soon as we hit a certain floor, wed all sit down instantaneously. People's reactions there were great.

My favorite was when we would cough or clear our throats one after another (staggered, so as not to appear suspicious, of course).
The person would often cough just to fill the silence after we'd all stopped.

Most amusing day at the office, ever.

I actually did an experiment similar to this in my social psych lab a few years ago. We looked and looked and couldn't find anything like this video. We tested peoples placement depending upon where someone was standing while facing the opposite direction. Good times.