I like the idea that we exported the term 'muppet' to America. Surely one of the most American of all children's entertainment (other than the Swedish chef). It is a great insult which should be used more often.
I think we should issue a very British 'Sorry' for giving them Chavs and Innit. But at least they know what a queue is, or at least the ones who have flown into Heathrow will know (much better than being 'in line').
In a previous job my US colleagues found is amusing that the UK version of the web site said 'Sorry' when no results were found, 'what are you sorry about?' Us Brits were of course proud of the fact that we were always polite to the user, even when they can't spell. We also would not let the US design team call the tabs at the top of the page 'flaps'. Eventually somebody had to explain why the immature Brits could not accept this terminology.