If you enjoy TED talks, you'll find the TED Radio Hour most compelling. Each show is dedicated to a different theme, such as the source of happiness, crowd-sourcing innovation, power shifts, or inexplicable connections. The episodes are co-produced by NPR and TED and visitors to the site can make their way through over a dozen programs. Some of the offerings here include "Africa: The Next Chapter," "The Future of Cities," and "Where Ideas Come From." The programs feature guest speakers and commentators from around the world, and could easily be used in any number of settings, including book groups, classrooms, and so on.