Thanks, rjay09 - good info.
Perambulator - I would not put protein shakes (or protein snacks) in the same category as steroids. Protein is a necessity, and if a person is exercising, more protein is often needed. Sure, some people overdo it. But an extra serving of protein (from whatever source) is a reasonable step for most people that are trying to build strength or muscle or are doing endurance training.