Hello.

By the way, I wonder why some people are hung up on the idea that the characters must have an English accent, is it simply because Terry Pratchett is English?

The Discworld is an entirely different planet in a different universe, but the countries in it are based loosley on different parts of this world, many of them not England. Ankh Morpork is thought to be a cross between a few cities around our world, such as London, New York and Philladelphia (sp?), yet it is none of those at the same time. It's a lot like York where I live, but not identical. It's supposed to be a boiling pot of cultures from all over the Disc so there would be all kinds of accents, including ones that might sound American (i.e the Stargate chap is a valid idea), and will probably have an accent of its own that belongs to Ankh Morporkers born and bread.

I think it would be more fitting to get people from lots of different nationalities to play the different parts.