Btw, it continues to amaze me how some actors can hide their English accents. I had no idea Andrew Lincoln (Rick) was English. You'd never know it by the series.

Same true of House (Hugh Laurie). Blew me away. How do they do it. Alex O'Loughlin McGarret from Hawaii Five-O actually is from Australia and has an accent in real life. Just my two cents but I don't know that an American could pull of a successful English accent (Rene Zeilweiger is the only one I know of)
TIS