The Protein Debate Featuring...
...Doctors Loren Cordain and Colin Campbell, each top-notch in their respective fields. Dr. Cordain has made his mark in the realm of Paleolithic nutrition and runs The Paleo Diet website and Dr. Campbell is a worthy adversary with is research into low-protein vegetarian diets and avoidance of all animal products. Robb and Greg over at The Performance Menu put this debate together and it's awesome. It's 33 pages long, but is well worth the read. In typical medical fashion, each doctor writes his essay and the opponent offers a rebuttal; there are no follow-up rebuttals. Take your time and digest it, then consider the arguments made and any questions that the two doctors may leave you with.
And if you care about nutrition, health, and exercise, along with some great recipes, subscribe to The Performance Menu. It's only $30/year for 12 issues. You won't find a better source for top-notch nutrition information (and unfortunately I get no money for saying that).