Yes, its that big question that everyone wants to know the answer to. Deep Thought computer thought he/she (no sexism here ) knew it, various religious leaders and philosophers thought they knew it, my dog thought she knew it (well, perhaps not), but it appears they are all wrong . Yes, here is the true answer to the greatest question the world has ever known...

WHAT IS THE MEANING OF LIFE?
I will begin by explaining why it is a question that is haunted the human mind for centuries, and why it is in reality a rather stupid question. You see, it is actually two questions: "What is the meaning of 'life'?", "What is life?", and finally, the main one: "What is the purpose of life?". I shall deal with the former first as it is easier and I'm tired.
"What is the meaning of 'life'?" : If you want to know, just take a quick trip here , and you shall immediately know the answer to all. Clicked? Good. Very interesting to know, of course, but about as philosophically useful as a chocolate teapot. So that is not the question we are asking.
"What is life?" : Now this is where it gets interesting. I will look back to one of those biology lessons I had in my first year of secondary school. We were taught the criteria that had to be met to be alive:

Movement
Respiration
Sensitivity
-----------
Growth
Reproduction
Excretion
Nutrition
What we got was 'Mrs Gren', a rather annoying lady, since she has got it all wrong. Take a flame running along a piece of wood for an example. Is it alive? Of course not. Yet it moves . It respires , by which I mean taking in oxygen and giving out carbon dioxide (which covers excretion , getting rid of waste. It shows sensitivity , reacting if you place an inflammable obstacle in its path. It grows as it consumes the wood. It reproduces , in a way. It uses oxygen to fuel its lust, covering nutrition . But it is still not alive, and Mrs Gren is useless. In fact, if I ever met Mrs Gren, I'd burn her house down.
So now we know that life is something different. I shall explain what it is. Find a yo-yo. Study it, and you will find it can only go up and down until you (or gravity) stops it. If you do not understand, try this example. Do you have a teddy bear? If so, go and fetch it. Sit it on top of your monitor. Stare at it hard. It will not move. It's not alive. You can rely on it totally and utterly to stay there (unless you happen to be experiencing an earthquake, in which case I would like to know why you are on the internet). What if that bear was real? It might stay still, it might toddle off to eat something, it might jump up and down after the yo-yo, it might make a nasty mess on top of your monitor, or it would most likely crush it. It is alive, and unpredictable. Throw your bear out of the window. There: you have proved that you are alive. So you now know what life is: spontaneity.
"What is the purpose of life?" : When you think about it, we don't really do much on earth. We are born, we live, and we die. That is what made people believe that death was not the end. But it is. It is what we are living for. We live to die; and we live to live, until we die. That's all there is to it. Our purpose in life is to stay alive for as long as possible, but, since death is inevitable, we also live to die. So you had better start living, because you're going to die soon.

And now I feel the need for an appendix, for you are asking "How can I live?". The answer is simple. Do something spontaneous, unexpected and entirely silly. You see, everything in the universe happens due to the exchange of energy: stars exploding, asparagus plants growing, me typing, you reading, all depend on an inequality of energy. If equilibrium is reached, there is no reason for anything to happen. If equilibrium is reached, life will no longer live.

So stand up and be counted in the war against uniformity; for we are armed with greatest weapon we know, and until some mice, dolphins or aliens come to steal the title, we have the most powerful organic brain we know of. Do something silly and unexpected every day; pretend to be a panda when listening to someone talk about current affairs, walk around on your hands for the day, send a virus to your enemy's computer, and once you've have done all that, sit down and read a nice book, just to confuse them.

I have passed on my philosophy of life to you, so go forth and multiply! I am off to do something incredibly silly.
This is bound to get closed, or even worse have people try to disprove everything everyone else says in the ensuing debate by means of numerous quotes with attached comments.

Cheers.

I think I prefer "42".

I know a joke about the meaning of life.

An angel and a dead man discuss about the meaning of life.

Dead: Maybe the meaning of life could be a family, a wife and children.
Angel: You did you came in that conclusion?
Dead: Well, didn't Christ blessed the marriage at Kanaa?
Angel: Aye, but he never made a family. No matter how his mother was arguing about it.
Dead: Arguing?
Angel: The common kind of mother..."When will you get married, when will i become a granny" ....they also say that before the secret dinner, she was really pissed off.
Dead: Why?
Angel: Here is how it goes. She was saying "I can't believe it Jesus, you are 30 and you only hang up with guys!!! They will say *stuff* about you." ...he replied "Don't worry mother, let them speak". Then holy mary asked "..where are you going?" and then the true fight started.
Dead: Why? What did he said?
Angel: He said "I am going to be kissed by Judah.