Time was when the only sounds in examination rooms were the rustle of paper, the scratching of pens and the boom from the chemistry labs downstairs as some unfortunate failed his practical with a bang not a whimper. Not any more, in Hong Kong at least. Warwick Business School, whose distance learning MBA is a big seller there, has been forced to tighten its regulations against the curse of mobile phones. Not because students have been using them as a high-tech crib, but as a consequence of invigilators being driven mad by bleeping from the bags and briefcases deposited with them by candidates.