There's a really nice podcast interview with Barnaby, about the Textbook Stuff project, on the Big Finish website.
http://www.bigfinish.com/podcast/
Just ignore the salesey stuff going on in the main page; on the left is a little podcast box, just click on the Textbook Stuff one. It'[s a really nice, intelligent and interesting (I think) interview about the stories and poems themselves, as much as about the project.