I've been thinking of this too. Wanted to write something but first Googled it and came here and saw that most of my thoughts have already been thought.
But who is the thinker?...
Bob's your uncle is really something that is very interesting to think about.
It's been suggested that the mimicking prisoner in the cell with Naido and Chad might be Billy because blood is pouring out of his mouth and Tina's daughter's Uncle may have been present when Billy jumped a 6 foot fence and ran into their house to bleed on their sink. The girl in the car of the incessently honking woman in front of the Double R who had to get home to see her uncle was also bleeding like that.
Gordon Cole: She's here visiting a friend of her mother whose daughter has gone missing.
A little bit uncle-y
Finally, I was convinced that Leland once said that he first met a Mr. Robertson when visiting his Uncle. I double checked and was wrong - he was visiting his Grandfather whose neighbor was Robertson. Damn!
Uncle Leland perhaps?
What about Cousin Maddy? I think neither the Diary nor the show mentioned what kind of a cousin she was. If she was Laura's first cousin, either Leland or Sarah were her blood uncle or blood aunt. Or not, if Maddy was a second cousin. I hope I'm not mixing up family relations. It's been a long day.
Blood uncle... *shiver*
Jerry Horne? He would be a great uncle to Richard and any other child of Audrey's.
Of course I am not convinced of any of this but Jerry is stuck in the woods and must have some role in this story. Uncle is one possibility.