In a departure from the data management good practice that I learned a while back, Google use the language setting for US English (rather than the proper one :) to determine how there apps work rather than simply the words , spelling, and punctuation used.
I discovered this as I set up a new apps account , accidentally left the default setting for language as US and discovered that I could use Google Voice to dial out to US and Canada for free from New Zealand. Not a big saving over Skype but a demonstration of how things are coming together in a common look and feel and set of services 'in the cloud'. Now your Google contact list is a one stop shop for outbound calling. Of course, there are ways of running a full Google Voice service outside the US but that requires a little more effort than putting up with a few odd spellings :)
The Google Apps dashboard also functions differently with US setting.
I am still a bit concerned that the gung-ho people from Google should misuse the language attribute rather than define a specific setting "Google-Voice-On". What next , identifying Europe by the use of the currency euro? Close enough?