Hey - so I think I'm going to end up learning a lot about being vegetarian because I am a major nerd and I will learn and learn about things because quite frankly, I spent a lot of alone time as a kid. So you have been alerted, nerd alert complete.
My source is the almighty Wikipedia (http://en.wikipedia.org/wiki/List_of_vegetarians#United_States) but I don't expect you to read all of that. The most important search for me was to find athletes who can sustain their performance while being vegetarians.
Right off the bat, no pun intended, Prince Fielder. That tub of lard? Or shall I say vegetable based fats? He surely gets his protein, averaging some 40 home runs a season for the Milwaukee Brewers and hopefully the Boston Red Sox someday. How about Bill Walton? That hippie. He's been through a lot though, and he seems like a pretty smart dude. Raja Bell, a basketball player who makes a living on playing good defense. Herschel Walker, one of the nastier running backs on Tecmo Super Bowl. Tony LaRussa, he's old and seems pretty healthy.
Okay so there aren't that many on this Wikipedia article, but I'm on the search for more. How about non-athletes, according to this 100% accurate and totally reliable source? Albert Einstein. Boom! Paul McCartney. Bam! Hayden Pennetiere. Schwing! Leonardo da Vinci. Code! And numerous former Playboy playmates, which I believe would include Miss Pamela Anderson.
I feel like people have been keeping this vegetarian thing from me for all this time, and to that I say, screw you, screw you you big jerks.