If vegetarian/vegan tell me why?

I think I started this blog by briefly describing why I am vegetarian, now I want to know if any of my readers are vegetarian and if so why?

I am vegetarian because I have always been idealistic, but more importantly because of philosophical thought, environmental concern and compassion. For philosophical reasons, it seems that it is human-based-bias against other species that allows us to cause animals massive unnessary harm, without thinking its wrong. It seems doubtful that the environment can sustain millions of livestock, nor can a diet based on animals feed the world (Think of the energy pyramid in biology. As one goes from plants to herbivores to carnivores, the total energy gets less). For reasons of compassion, I think it is wrong to use and kill animals for food, which causes billions of animals to suffer every year.