In London, recent protests in favor of animal testing (no need to email us, veggies, we know) got our business columnists John Elkington and Mark Lee thinking: is there a place in the lab for human subjects? A growing number of researchers think so. It's not as callous as it sounds: These folks are studying ways that big businesses can reach -- and help -- the 4 billion people at the bottom of the world's wealth pyramid. Find out what they're up to in today's Full Disclosure.