A driver is stuck in a traffic jam on the motorway. Nothing is moving. Suddenly he sees a group of men carrying collection buckets walking down between the lines of cars talking to the drivers. One of them knocks on his window. The driver rolls it down and asks, "What's going on?" "Terrorists have hijacked the car that Tony Blair, Gordon Brown and David Cameron were travelling in. They're asking for a Â£300 million ransom, otherwise they're going to douse them with petrol and set them on fire. We're going from car to car, taking up a collection." The driver asks, "How much is everyone giving, on average?" "About a litre."