You need to make a us email address then make a account with that email and that account will then be a us account dunno if netflix will work as it may go by IP address but you can get us only dlc (there is a free us arcade game called Aegis Wing) and us
only insider moves ect
C) since that last post, Netflix has announced it will be out in the UK next year. No details about xbox live support yet, but seems reasonable to assume they will continue their partnership with xbox.
Even if you had an American Account on your Console, as Cosmic has stated, due to licensing laws your UK IP Address would be blocked from seeing the content, you could put points on your US Account and it will detect the region you are in and you will get
the message that you are not allowed to view this content in your region. Netflix is coming to the UK in early 2012....just be patient