From the Guardian, today:
New York has been celebrating the semicolon; a development as welcome as it is unexpected. According to the New York Times, an announcement about the disposal of newspapers, posted on the city's subway, which was to have read: "Please put it in a trash can, that's good news for everyone" was amended by some scholarly hand in the marketing department to insert a semicolon in place of its comma. Congratulations have followed, and rightly; it is usually seen as bad practice to join two sentences together with a mere comma, that is something only the semi-literate do. "In literature and journalism, not to mention in advertising", the New York Times reports, "the semicolon has been largely jettisoned as a pretentious anachronism." Not, however, in the Guardian, whose most famous editor was unusually fond of the creatures. The speech in which he declared that comment was free but fact sacred is peppered with them, as in: "It is well to be frank; it is even better to be fair." That is how the semicolon ought to be used - as a kind of necessary staging post on the way to the end of the sentence; or as the great authority Fowler put it, to indicate "a discontinuity of grammatical construction greater than that indicated by a comma but less than that indicated by a full stop". This is, of course, dangerous territory; where pedants are on the prowl. Even the best intentioned will sometimes blunder; but as Alexander Pope impeccably said: "To err is human; to forgive, divine."