No, this has nothing to do with the gay marriages thread. :D
Simple: Start a sentence describing the next poster in the thread. They finish it, and start one of their own.
Example:
Poster #1: The person below me loves the taste of...
Poster #2: ...bananas, while the person below me believes you should never...
And so on and so forth.
I'll start:
The person below me likes to watch...
