Meanwhile, I wonder what Cambridge Consultants are going to do with a dataset of thousands of Hacker News users reading out the sentence "Please call Stella and ask her to meet Bob the frog at the store with three small red plastic bags".
The sentence is obviously taken (with some modifications) from the sample used by the speech accent archive ( http://accent.gmu.edu/howto.php ), which was constructed specifically to include every relevant phonological context in American English. (Not that this was necessarily achieved, but it was the goal.)
I can reliably fake a British accent although I seem to get stuck on frog and store still sounding American. When I do the stereotypical Texas style "yee haw" accent I get 99% American.