Narnia Code?

Came across this intriguing bit of documentary on BBC iPlayer (love that thing! great break from studying :P) about this guy who worked out the secret behind CS Lewis's Narnia collection. Perhaps the documentary makes it out to be a much bigger deal than it probably is, but it's definitely an interesting theory, that only adds to our understanding of the literary genius that is CS Lewis. The guy with the theory is a pastor, by the way, and he has a website about it and the book he wrote about it. (You non-UK people will have to be content with the website, as BBC iPlayer can't be accessed outside the UK.)