I was doing a little Googling on "Mary, Mary, quite contrary" to find out the origin of this nursery rhyme. Mary Mary is a main character in the book along with Jack Spratt. I happened upon this very cool site called The Visual Goose. It includes intriguing illustrations of nursery rhymes along with explanations of them based on history, mythology and literature. I also like the discussions from site visitors of the rhymes based on their knowledge.
And Jasper Fforde's new book, The Fourth Bear is coming out at the end of this month so I don't have to wait very long for the new adventures of the Nursery Crime Division!