Roger Sutton of The Horn Book and Read Roger has started a game:

I also have a new game inspired by my allergic reaction to the title of Jerry Spinelli's latest book, Smiles to Go. It got me wondering why children's book titles seem to tolerate more sugar than do books for adults, and that got me thinking about what adult books with children's-book titles would be like. For example, Tuck Everlasting is surely a Jan Karon novel, last in a series, about the picturesque town of Tuck, itself tucked away in the timeless foothills of the Piedmont. And The Chocolate War is by John Le Carre and involves Colombian narco-terrorism. Charlotte's Web? Linda Fairstein thriller about an internet-adept serial killer in stilettos.

My favorite from the comments: "The Lion, The Witch, and The Wardrobe: a vicious tell-all about the marriage of Richard Burton and Elizabeth Taylor." Hilarious!