Quentin Crisp, the infamous, bohemian Englishman, said that he never cared much for dusting. “Why bother”, he observed, “after four years, it doesn’t get any worse”. If only the accumulated detritus of the digital dust on our computers could be treated with such cavalier contempt. Ignore it at your peril and you might just have to call in Kim and Aggie to sort out your cruft!