S.E. Hinton (author of The Outsiders) looooooves Supernatural (Jared Padalecki!) and has appeared in several episodes!
Flavorwire Exclusive: S.E. Hinton on her epic love of Supernatural
I'm actually not surprised that authors are interested in this series. Husband was just talking the other day about how Supernatural seems like a vehicle to look at adorable boys acting bad ass, when in reality, it's actually too in-depth of a show for him. The story lines are epic and historical... it's just a pleasant side effect that Sam and Dean Winchester are so nice to look at.
P.S. The Books section of Flavorwire is full o' amazery!
P.P.S. My sister's favorite book/movie is The Outsiders. We recently had an argument over which was the better show... Charmed or Supernatural. Sorry Linds... it's clear that Supernatural wins if the author of your beloved story prefers The Winchester Brothers over The Charmed Ones.