Dialect Coaching for the American Accent
(partial client list)
Teoman, Andrea Osvart, Raoul Bova, Rachelle Wood, Paul Leyden, Kristina Rihanoff, Carla Ortiz, Sandro Finoglio, Carla Sanchez, Patrick Nuo, Kathrin Rein, Kimi Verma, Ami Fuse, Gerardo Gudino, Neko Zhang, Sissy Gamache, George Cruz, Paul Hodge.
and more actors.
Want to learn more about accent reduction on wikipedia?
Resources for Actors
Pronunciation Interactive Chart