For over a decade QI has been the smartest comedy show on British television, but few people know that they are also a major legal hit in Australia, New Zealand, Israel and Africa and an illegal one on BitTorrent. They also write books and newspaper columns; run a thriving and recently redesigned website, a Facebook page, a Twitter feed; and produce an iPhone App and a sister Radio 4 programme.

At QI's very core is the astonishing fact; painstakingly researched and distilled to a brilliant and shocking clarity. In Einstein's words: 'Everything should be as simple as possible, but not simpler.'

Pigs suffer from anorexia.
Wagner always wore pink silk underwear.
Rugby School's first official rugby kit in 1871 included a bow tie.
Lord Kitchener had four spaniels called Shot, Bang, Miss and Damn.
It is impossible to whistle in a spacesuit.