Tonight, BBC Two is screening all six episodes of the first series of The Office, the landmark comedy that transformed the sound of fingernails being dragged down a blackboard into laughter. And like the commentary on a DVD, the episodes are interspersed with insights from Ricky Gervais and Stephen Merchant, the co-stars Martin Freeman, Lucy Davis and Mackenzie Crook, and famous fans including Richard Curtis, Ben Stiller and Hugh Jackman.