Longevity, banging on and on, is the key component of national treasuredom. In his slick Sale of the Century years it was hard to imagine Nicholas Parsons might ever achieve the status, but now, aged 94, and having presented 975 episodes of Radio 4's Just a Minute/c], without deviation but with plenty of repetition, the mantle maybe fits. The BBC celebrated his half century with a tribute, Just a Minute: 50 Years in 28 Minutes, which had living panellists compete with departed wits; a ouija board parlour game. Paul Merton interrupted Peter Cook's 60 seconds on the Loch Ness monster, Jenny Eclair was superseded by Patrick Moore on foolishness. By the time Stephen Fry cut in on Kenneth Williams and Barbara Castle on the subject of Gregorian chants, it was tricky to work out who was in the studio and who wasn't. "I don't think we can have psychic challenges," a youthful Parsons reminded his departed guests; we can now.