A horse trots into a bar; proprietor asks, "Why the long face?"
Well, this ain't a cracker jack, but I've always liked it:
Airforce One is flying World Leaders, the Pope, the Dalai Lama, the Head of MENSA and an Australian Backpacker back from an important conference when the pilot suddenly announces: "Attention, we have multiple engine failures and need to ditch into the Atlantic. Unfortunately, owing to the unplanned guest on board, we are one chute short; you'll have to decide who stays on board."
With that, the pilot jumps from the craft leaving everyone stunned. With that, George Bush stands up, "I'm the President of the United States of America, leader of the World's most powerful nation, the world needs me." With that he grabs a chute and jumps out.
The Pope stands up and announces that "as head of the Catholic Church and spiritual leader to billions, the world needs me." He too grabs a chute and jumps.
The process goes on until there's just three people left: Sir Clive Sinclair stands up: "As the head of MENSA, the organisation of the most intelligent people of the world, I am also too important to stay behind." With that he grabs a pack and jumps.
The Dalai Lama turns to the backpacker and says, "My son, I believe in the hereafter and continuity of all things; please take the last one and be safe."
The backpacker sits up and, handing the Dalai Lama a pack, replies: "No worries mate, the most intelligent man in the world has just taken my rucksack."