Learning center. Acquire lots of skills — from organizing your daily life to mastering Google Desktop — from Hewlett Packard's online classes. Each class includes up to 10 lessons and may also include interactive demos, assignments and quizzes.
WonderHowTo. Curators scour more than 1,700 websites and hand-pick instructional videos — from how to live longer (with University of Cambridge researcher Aubrey de Grey) to teaching your dog to roll over and play dead.
Videojug. This British entry features thousands of "how to" and "ask the expert" videos on a seemingly endless array of topics.
TEDTalks. Since 1984, the annual conference that goes by the acronym TED (Technology, Entertainment, Design) has brought together some of the world's top thinkers and doers and challenged them to give the talk of their lives in 18 minutes or less. This site aggregates the best of those, including Australian science writer Margaret Wertheim's presentation about the beautiful mathematical links among coral, crochet and hyperbolic geometry.
Nobel Prize winners. The online home of the Nobel Prizes is packed with interviews with and lectures by some of the world's smartest people. There's an interview, for example, with Italian neurologist Rita Levi-Montalcini, the first Nobel laureate to reach the age of 100. (She and a colleague won the 1986 Nobel Prize in physiology or medicine for their discovery of nerve growth factor.) In it, Levi-Montalcini talks about why this latest period of her life has been the best.
Forum National Network. A consortium of public television and radio stations offers live and on-demand lectures by some of the world's foremost scholars, authors, artists, scientists, policymakers and community leaders. Recent lecture webcasts included Harvard sociologist Sara Lawrence-Lightfoot discussing her new book, The Third Chapter: Passion, Risk, and Adventure in the 25 Years After 50. The best starting point for accessing all the multimedia content is through the website of one of its members, the Boston-based WGBH Forum Network.
Big Ideas. This site, courtesy of TVO, Canada's largest educational broadcaster, presents lectures on a variety of thought-provoking topics that range across politics, culture, economics, art, history, science and other fields. There's even a "Best Lecturer Competition."