Is there any difference between Microsoft’s US and UK Vista and Office?
I am thinking that I should get a mate to buy them in the US and post them to me. That way I would only pay 1/2 price.

I think they’re the same. I bought the Vista Ultimate OEM version in UK (from France) and the US version was exactly the same product number.

Half price, I guess it depends on where you buy and what version you buy. The Ultimate OEM version cost me about €200 with shipping and VAT from UK (£123 including VAT + £10 shipping), it would have cost me €160 w/o tax if I had it shipped from the US. With some research I would have certainly found it a little cheaper but not half-price. Office prices may be different I don’t know.

The way the dates are displayed,

US = month day year
UK = day month year

measuring systems

UK = Metric
US = imperial

and the aforementioned language differences resulting in the incorrect
spelling [1] of some words eg:

colour
a lot of words ending in “ize” instead of “ise”

etc

[1] as the language is English then I guess the British have the right
to decide the correct spelling ;o) As Winston Churchill observed, “the
UK and America are two countries separated by a common language”