Can you solve these puzzles?

1. There is a man who lives on the top floor of a very tall building. Everyday he gets the elevator down to the ground floor to leave the building to go to work. Upon returning from work though, he can only travel half way up in the lift and has to walk the rest of the way unless it's raining! Why?

This is probably the best known and most celebrated of all lateral thinking puzzles. It is a true classic. Although there are many possible solutions which fit the initial conditions, only the canonical answer is truly satisfying.

2. A man and his son are in a car accident. The father dies on the scene, but the child is rushed to the hospital. When he arrives the surgeon says, "I can't operate on this boy, he is my son! " How can this be?

3. A man is wearing black. Black shoes, socks, trousers, lumper, gloves and balaclava. He is walking down a black street with all the street lamps off. A black car is coming towards him with its lights off but somehow manages to stop in time. How did the driver see the man?

4. Why is it better to have round manhole covers than square ones?

This is logical rather than lateral, but it is a good puzzle that can be solved by lateral thinking techniques. It is supposedly used by a very well-known software company as an interview question for prospective employees.

5. A man went to a party and drank some of the punch. He then left early. Everyone else at the party who drank the punch subsequently died of poisoning. Why did the man not die?

6. A man walks into a bar and asks the barman for a glass of water. The barman pulls out a gun and points it at the man. The man says 'Thank you' and walks out.

This puzzle claims to be the best of the genre. It is simple in its statement, absolutely baffling and yet with a completely satisfying solution. Most people struggle very hard to solve this one yet they like the answer when they hear it or have the satisfaction of figuring it out.