I've seen this in many forums, and i enjoy it. So here goes:
The rules are simple, the above poster posts something like this:
"I wish that RPPR had a convention hall"
And the member who posts after him would say something like:
"Granted. Except that it has only cramped room to game in, with a few rotting pizzas here and there. And a gremlin."
Get the picture? I'll start with something simple.
I wish I had a billion dollars!