Destiny - is it fixed?

Today while comming to office in my cab I had a conversation with my friend. The conversation started with marriage (will write a post on it soon) and somehow turned towards destiny. My friend said he believed in creating one's own destiny; that one's destiny is not fixed but one has the ability to make one's own destiny. I said I didn't agree to it and that one's destiny was fixed. We didn't come to any conclusion and our conversation ended when he got a phone call.
I have always believed that one's destiny is fixed. But the path towards one's destiny is not fixed. Everyone can choose his/her own path. One might not take the shortest route but eventually one would reach where one is destined to reach. One may have a smooth sailing or may be caught in a storm but either way if one is supposed to reach somewhere s/he will surely make it. There are people who say that one has the ability to make one's own destiny by working towards it. I have seen many cases where in people have given their best efforts yet they didn't achieve what they desired. Its not that they didn't try enough; its just that they weren't meant to get that.
One might question - "If one's destiny is fixed then why should one do anything? Whatever is to happen it will happen no matter what". Point taken. But even if your destiny is fixed you have to work towards it. Nothing happens without any action. For one, you don't know your destiny; so no point doing nothing. Then you can't just do nothing - at any time you would be doing something; and that something will take you towards your final destiny.
But the question remains "If your destiny is fixed what is the point putting in the effort?". The reason you need to put in the effort is because you want to enjoy the journey. You don't know your destiny and finally reaching there might not be well accepted by you. But what you can do is make the choice of the path to take, the road to travel and to do things you want to. Why waste today worrying about tomorrow.
There are people who believe in God and there are people who don't. Some common beliefs among people (especially spiritual and religious sorts) are God controls everything and whatever happens is done by Him. But then there is someone (I am forgetting the name :() who has said things a little differently and I quite liked what he said. He said that God is central to everything; but its like tying a rope around a cow and tying the other end of the rope to a nail or tree. The cow has the freedom to move in a specified area (equal to the area of a circle with radius equal to the length of the rope); but it can't move beyond it.
Its just how you look at things and believe in them. Whatever you believe in truly keep following it and you will reach where you are meant to. The most important thing is to enjoy the journey.