I was watching "It's a Wonderful World" the other day and Jimmy Stewarts comic attempts at fake accents reminded me that I don't think I've ever heard him use a dialect outside his distict own voice. I wrote a review about it on my classic movie blog [MacGuffin Movies|macguffinmovies.wordpress.com].
I know the ability to do an accent doesn't make you a spendid actor or that not being able to do one is a detriment to talent, but it certainly helps, right?