Yeah, we could do that, although there are a lot of countries that speak English but people seem to either use the US or UK variant as far as I can tell.

The differences are mostly in the 'locale' issues, especially dates. I got around that by doing 'Jan 1st 2009', in stead of the strictly numerical options.

The language issues are less of a problem, they're minor spelling issues such as 'colour' vs 'color'. I never had any complaints about those.

Australians and Canadians have long ago dropped most of their English spelling details, Americans don't care too much from what I can see. Some very purist English folks have sent an email or two (one about 'gray' vs 'grey', go figure...) but for the most part it is just whatever works.

There is a lot of tolerance for this in end users, they understand that you have to make choices.

Here was an interesting thread on this not that long ago:

http://news.ycombinator.com/item?id=741093

It's not quite true that Canadians have dropped British spelling. Careful writers still follow British conventions, but no Canadian will be bothered by US spelling on a site that is directed at an American or international audience. Some people will notice and mind if the site appears to be a Canadian site targeted at Canadians (e.g. a Canadian government site).

Well, I've lived there in total for about 5 years and nobody in all that time ever remarked on this, but I did notice that older Canadians tend to favour (...) British-English spelling, the younger generation is much more US-English slanted.

Agreed on the governmental stuff, that's where the big differences are, but then again, those have to be bi-lingual anyway.

Ha. I double dare you to ask an Australian how you spell colour or authorise. They'd argue with you about them not being English 'details' but rather American 'misspellings', too.