I am well aware of Peter Singer, read Animal Liberation.
http://www.youtube.com/watch?v=9xxdMUuZXUY
Great video with Singer and Dawkins on eating animals.
I have to say I am rather put-off by the vitriol of so many here against vegans/vegetarians. Not sure I understand why what someone else is eating or not would cause so much anger in people, I find that very strange.