Speaking of accents - I find if I'm around people long enough with a different accent, I'll start to gradually adopt their accent (sometimes without even realizing it).
Once I was complaining to a co-worker about my boss. She kept laughing which seemed a bit uncaring to me since I was revealing some very emotionally painful situations. I asked why she was laughing at my claims of employer abuse. She said, "because you do him so well - you sound exactly like him - you've got all his mannerisms down and everything!" Funny thing is, I wasn't even trying to "do" him, nor was I aware that I was imitating him, I was just relaying various interactions my boss and I had.
I've always had an innate talent for mimicry, but one which works best when I'm not trying to imitate or am unaware I'm performing an impression.
I knew a woman who married a man of Middle Eastern decent. They moved overseas for a career opportunity near his parents and within a few years, SHE spoke English with a Middle Eastern accent, despite born here, parents born here, etc..
When I was traveling, I also noticed I might pick up a tiny little thing, how I would say "Oh, okay" because of all the people I was around. In a hostel, there would be people from over 50 different countries, and at night, we'd have some cool conversations, like little representatives how each of our country 'operates', and the things we talk about in here -- movies, which seem to have the most influence, no matter how educated one is, they always think of the US how Hollywood sees it. It's not until they make a trip to the US to see how different it is from their expectation, but also the different landscapes, time zones, etc., with such a large country with 350 million people.
And this reminds me of a friend of mine from Estonia (met in Australia), and he talked just like my older cousin, acted like him, had the same sense of humor, the cynical expressions he'd make, the observations, being quiet unless he had something to say, which was usually of some weight -- funny or profound. I think I had a chance to tell each one of them. I always would wonder how it would be if they met (especially if I never notified who/why I gathered us all together)