Maureen Johnson interviewed at Trashionista.

From the interview:

Where do you like to write your books (in bed, a coffee shop, an office)?

Either at my desk or at a coffee shop with other writers. Never in bed. I think it is my fake Catholic upbringing that prevents me from reclining while working. But since I'm only fake Catholic, I'm okay with slumping.

She also gives some writerly advice and mentions that she's about to start reading Skin Hunger.  Hooray!  Love that book.