Larry Brilliant, executive director of Google.org, asks whether we should be optimistic or pessimistic about the future of humanity.

In Britain, something is happening that hasn't happened for 100 years. More people are becoming incredibly wealthy, not only through inheritance, but also because of their own hard work.

Roger Martin, Martin Fisher, Mindy Lubber, Taddy Blecher, and Roshaneh Zafar wrap up the 2007 Skoll World Forum conference with inspiring final thoughts about how to take innovative ideas for social change to that tipping point where they can create large-scale lasting positive effects.