This week the Economist features an article called "One less brick in the wall," about China and the press. But it struck me, shouldn't it be "One fewer brick in the wall"? I mean, where is this rule going if the Economist violates it? Perhaps I don't understand the rule of less vs. fewer(?).
If you can count them, then you use "fewer," if it's uncountable (like "water") you use "less". So what's the story?

Literal minded thinks about the subject but doesn't really give me a definitive answer. Tenser the Tensor discusses it too, but I don't agree because I think that "fewer" can be used with a singular noun.

"One fewer wheel than the other cars" for instance.

And there is a reason for this rule. As one poster said:

"Since "less" is also used as an adverb ("less successful"), "fewer" helps to distinguish "fewer successful professionals" (fewer professionals who are successful) from "less successful professionals" (professionals who are less successful)."

And to top it off, there is an entire ad campaign for a drug called Gardasil combating cervical cancer called "One Less."