'WHO'S that one with the white hair?' was the most common question at last weekend's party to celebrate the 30th anniversary of the Sunday Times Insight feature. It could have referred to scores of the 150 or so guests, some of whom had not seen each other since working for Insight many years previously. Andrew Neil, the paper's editor, had given pounds 1,000 towards the bash but did not attend, while Harry Evans, one of his predecessors, sent a jokey greeting from New York. Under Mr Evans, Insight became well known for major investigations, but Clive Irving and Ron Hall, two of the original 1963 team, recalled that it began - under Mr Evans's predecessor, Denis Hamilton - as a tame digest of innovations in the arts and sciences. The investigations began later, almost by accident, with Mr Hall's dissection of the Profumo scandal.