Pretty simple, someone starts off (on this occasion, me) by making the thread then the next poster says something about them. The poster after them will have to say something about the person under me, gettit?

So eg, the next poster could put:

"The person above me has a low post count."

Then the next poster says something about the person who said that.

I hope I explained ok...and I hope it's not been done before. :)