The battle for the billion has been lost, but it is only very recently that the
American billion has edged out the native one, like a
predatory mink. Youngsters like the noder above
(now deleted, but who thought the British had used the American method for ages), assuming they've been aware of large numbers for only half their life, might have grown up thinking a billion was only a
thousand million, but for a large number of us (a different large number) the word is now just
ruined and
unusable. We know the newspaper really means a thousand million when they use it, but we can't ourselves change our upbringing and accept such a blatant
Americanism.
The first recorded use of billion in English was by John Locke in 1690, in the logical sense of million million that prevailed for three hundred years thereafter.
The change in Britain first took place as far back as 1974, when Harold Wilson's government decided to use American billions in treasury figures; however, I find it hard to imagine anyone much in the 1970s using the word naturally like that. It is only in the last ten years or so that I've been aware of the American usage appearing widely in newspapers and even, the last place it should appear, in scientific writing: scientific popularizations, anyway, perhaps because they're intended to sell on both sides of the Atlantic.
To digress: Some of these popularizations employ an even worse confusion: they describe a star as yea-many thousand billion billion light years away, or a drop of water containing so many billion billion billion somethings. Is this supposed to make it easy to visualize instead of hard old scientific notation? What difference does it make to anyone's understanding if the word occurs one time or five? And why do they always phrase it in billions, instead of trillions, quadrillions, or whatever is required? The answer is of course that no-one has any real idea what a quadrillion is. The fact that British and American ones are radically different is a minor inconvenience compared to the fact that you're way beyond meaningful comparison anyway.
We already had a serviceable word milliard for a thousand million; there was no need to import an Americanism. All we can hope now is that the whole system of number words will wither away and people will get used to exponent notation, or terms created from prefixes such as giga and tera will take over.
Billion in French had the meaning of milliard between the early 18th century and 1948, when they reverted to the standard usage in the rest of the world. However, by then American usage had already adopted the sense billion = milliard.
www.alt-usage-english.org/excerpts/fxbill00.html reminded me of the date and prime minister who started the rot, and gave the history of the French system.
www.worldwidewords.org/articles/numbers.htm also covers it and lists which cultures use which system, millions or thousands - it is based on
www.linguistlist.org/issues/7/7-451.html , a survey by the linguist Bernard Comrie