The birthday girl has blogged today! And has linked to an interesting article with the flawed deduction that Northerners speak properly! The article mentions the classic Barth/Baff debate amongst others.
I mention this becuase I've just come across an article on the BBC website, which says that the influence of Asian/Caribbean accents is having as pronounced an affect on regional British accents as the spread of estuary English.
Obviously some people give the game away as soon as they open their mouths. My Essex/London origins are probably obvious to all. Equally Diane and CP sound distinctly Northern.
Curiously I rather like going to different places and hearing different accents. I find it slightly disturbing to be in Cornwall or Derbyshire and to hear everyone speak the same drawl. Or to hear a Scott sound distinctly more "Surrey" than the natives.
I remember the first time the Sri Lankan cricket team toured. Test Match Special had a special guest commentator from Sri Lanka who made Brian Johnston sound common!