Vegetarians could be extinct one day. In-Vitro meat may be a way to produce large volumes of meat protein more efficiently than raising whole animals. I'm not sure that an in-vitro steak could possibly have the same texture or flavor as the real steak I eat but I'd be willing to give it a try. This is the only PETA supported effort that I could possibly get behind. It does raise some interesting ethical concerns though. If you could create meat without raising or killing an animal--what's to stop the production of human in-vitro meat? I could see McDonald's serving a quarter pounder people burger with fries. 
http://www.cnn.com/2009/TECH/science/08/07/eco.invitro.meat/index.html
http://www.cnn.com/2009/TECH/science/08/07/eco.invitro.meat/index.html