Draughty
A man died and went to Heaven. As he stood in front of the pearly gates, he saw a huge wall of clocks behind him. He asked "what are these clocks?"
St Peter replied "Those are lie-clocks. Everyone on earth has a lie-clock. Every time you lie the hands move."
"Oh" said the man "whose clock is that?" That's Mother Teresa's" said St Peter, "the hands have never moved."
"Incredible" said the man "and whose clock is that one?"
St Peter replied "That's Abraham Lincoln's, the hands have only moved twice."
"Where's David Cameron's clock?" the man asked.
St Peter replied "We're using it as a ceiling fan."