The "Columbia Journalism Review", a magazine for reporters, often has
> ads by corporations reminding people about using trademarks as
> everyday words. I guess the most common example today is using
> "Xerox" as a verb ("go xerox this letter") or a noun ("I'll send you a
> xerox of the letter"). It is a trademark and is properly used to
> describe a particular brand of copier machine or the company that
> makes them: ("I'll run them off on our Xerox machine").
Xerox isn't used in a generic sense quite so much in Britain as in the States, but we have plenty of other examples.
"Hoover" is commonly used both as a generic name for any sort of vaccuum cleaner, and as a verb, e.g. "I'll just hoover up" or even "I'm going to do the hoovering." The Hoover name never became generic for any of the other types of appliances they made, such as irons and refrigerators. Had the latter been the most widely associated product of the company, maybe today people would talk about "Getting some milk from the Hoover." Sounds weird, but it could have happened.
-Paul