I was on Zach Sherwin's Watch Your Language last night to talk about Lindsay Lohan's strange new accent. It was a fun show. You can see it on Alpha now, and I understand it'll be on Youtube before too long. You can hear her sound a little bit Turkish, a little bit...some other stuff in this video.
The quick version of what I said to Zach last night: accent is identity. Identity is a construction of self, even if mostly an unconscious one, and can be quite fluid. However striking Lohan's case is, it's just a pronounced example of something most human beings are doing most of time, even if in a far subtler way.
It was a thrill for me to be on the show with sociolinguist Nicole Holliday. Dialect coaches have a lot to learn from linguistics, and sociolinguistics is particularly applicable to what we do. (I'd also respectfully submit that they have a thing or two they might learn from us!)