i'm surprised only one person has mentioned that field animals get killed in the harvesting of vegetarian foods. If you're a vegetarian for ethical reasons, then I think you should be eating your own stuff out of your own garden. Otherwise, you're still killing animals.
http://www.wildlifedamagecontrol.com.../leastharm.htm
according to this, the foods grown for vegetarian diets actually kill MORE animals than killing animals for food. So unless you've got your own garden (or you don't eat meat for non-ethical reasons), you might as well enjoy some good ole fashioned steak.