Thanks for your response, I think it's the most thought out so far.
Again I'd like to reiterate the fact that I do not disagree with spaying/neutering your pets. I have two kittens myself that are going in to the vet next week to get fixed. I think more can be done to care for abandoned animals and I don't think that all animals need to be spayed/neutered. But that is a personal opinion.
The reason I brought up this topic was not to say that spaying or neutering your cat is a bad idea, or that human beings shouldn't have children. I just think that this topic needs to be explored. I think the world needs to change in many many ways and the first step to change to ... well discussion, thinking things through etc.
There are a lot of unexplored questions. For example, what are your thoughts on breeders? I think there should be laws against that type of thing. People shouldn't be able to make money off of selling a living creature.