The associated 'record your accent' survey is gathering pace, with over a hundred recordings up already at this website. My idea is to collect as many versions of the way people say a single word ('potato') as possible, on a worldwide scale, so that we can hear the subtle gradations that occur from place to place, and of course even within a place.
My thanks especially to Stephen Fry, Michael Rosen, John Humphrys, Benjamin Zephaniah, Nicholas Parsons, Brian May, and Pam Ayres, who were among the first to let me know how they say potato - often with some unexpected additional remarks!