When is a mile not a mile? When you rack it up gassing on the telephone: if as well as flitting around all over the place, you spend a lot of your time adding to the phone company’s profits by gossiping for hours long-distance – and you’re a non-smoker – you can count every dollar you spend with MCI Communications as another mile flown under Northwest Airlines’ frequent flier programme, which rewards those who endure enormous numbers of hours aboard Northwest’s aircraft; and non-smoking? Northwest is one of those illiberal airlines that have banned it altogether, so if you’re a smoker, you’re not likely to chose to put in those frequent flyer miles with them.