Okay - the short version first. Slashdot is a US-centric site. It says so in the FAQ, and I understand and respect this. Sometimes I may slip up and write colour instead of color, but hey, I'm making an effort, and I consider that to be the polite thing to do.
Getting in to it a bit longer now, and probably earning myself a severe beating at the hand of my fellow Royal Berkshire neighbo(u)rs... I have always done this sort of thing. If I go abroad someplace, I try to learn some useful phrases. I have learned a little Spanish this way, (very) little Greek, a few choice words in Afrikaans, and the odd (spoken) Japanese phrase. I learned French and German at school, and whilst my German is rustier than a 20,000 year-old Ford, I have had occasion to use my French whilst in France and Belgium, and often on the phone to the Paris office at work. I might end up being crap at it, and at least two thirds of the Paris office speak better English than I do French, but I'm being polite and showing willing. This isn't always appreciated, especially in Brussels, where you might *think* it'd be a good idea to speak French, but you can end up really pissing off the Flemish-speaking population if you just assume that everybody speaks French.
End of the day- if I'm writing an email to somebody in Boston, Lincs, England, I'll tell them that the cheque's in the mail. If I'm writing for somebody in Boston, MA, US, I'll tell them the check's in the mail. It's really no big hassle. There's a great site about the differences in language usage over at the pages of Susan Jones at Georgia State University, and more over at the pages of The Oxford English Dictionary.
The one exception to all the above is router. I simply couldn't bring myself to pronounce it differently unless I was stood in a room with just me and various Americans or Australians. English is a very rich and varied language, and there should be enough room for all of us to get on without squabbling, but I'm sorry, I just don't like this one...