Natascha McElhone (from the UK) portrays David Duchovny's ex-wife in
Californication. She mostly does a decent job with 'merican, but it kind of falls apart in scenes where her character gets angry or raises her voice.
If you check out Gillian Anderson's bio, her family moved from London to Michigan when she was a kid, and she adopted a midwest accent to blend in. She's switched accents ever since, depending on what part of the globe she's in. Essentially acting in her daily life.
The weird thing is that her entire persona seems to change according to the accent. Check out these two clips ... the first one is her being posh and serious with a British interviewer, the second one is her acting frisky with Letterman:
http://www.youtube.com/watch?v=p45QBXRIgws http://www.youtube.com/watch?v=b2Z8UvXjgG8Other glamorous impostors : Charlize Theron (South Africa), Famke Janssen (Netherlands).