because this sort of thing is my 
kind of nonsense.
now if your browser lists en-GB in the Accept-Language header, then you'll see the US spelling (favorite) above, otherwise you'll see the UK spelling (favourite). neat, huh?
okay but note that other world englishes are often split on the spelling and that can make it very funny. philippine english generally goes for the american spellings, most former-british-colony englishes go for the UK. en-PH is actually coded into some language handling systems have fun
the real power play here I feel is to be Canadian, since they just kinda split the difference between US and UK spelling more or less down the middle
