Okay, the idea of this one is you write out your wish, and the person that post next grants it in a funny way and then writes their own- Like this.
I wish... That I could have a million dollars.
The person next would reply:
Your wish has been granted.
You've suddenly won the lottery and made a million dollars but then a seagul comes out of nowhere and carries it off to it's nest. You're broke.
Then THEY'D make a wish.
I wish I had a new car, and so on and so forth.