Susan notes: Thanks to TED for making TED Talks downloadable and embeddable, and for providing the biographical information that goes along with them.

This demo -- from Pattie Maes' lab at MIT, spearheaded by Pranav Mistry -- was the buzz of TED. It's a wearable device with a projector that paves the way for profound interaction with our environment. Imagine "Minority Report" and then some.

Pattie Maes was the key architect behind what was once called "collaborative filtering" and has become a key to Web 2.0: the immense engine of recommendations -- or "things like this" -- fueled by other users. In the 1990s, Maes' Software Agents program at MIT created Firefly, a technology (and then a startup) that let users choose songs they liked, and find similar songs they'd never heard of, by taking cues from others with similar taste. This brought a sea change in the way we interact with software, with culture and with one another.

Susan notes: Thanks to TED for making TED Talks downloadable and embeddable, and for providing the biographical information that goes along with them.

Samantha Power tells a story of a complicated hero, Sergio Vieira de Mello. This UN diplomat walked a thin moral line, negotiating with the world's worst dictators to help their people survive crisis. It's a compelling story told with a fiery passion.

Samantha Power is head of Harvard's Carr Center for Human Rights Policy, where she studies US policy as it relates to human rights, genocide and war. She's the author of a famous memo (in policy circles) suggesting that US foreign policy is utterly broken -- that the United States must return to a human rights-centered foreign policy or risk its prestige and respect in the world community.

Susan notes: Thanks to TED for making TED Talks downloadable and embeddable, and for providing the biographical information that goes along with them.

Singer-songwriter Nellie McKay performs the semi-serious song "Clonie" -- about creating the ultimate companion.

Playful, quirky, hilarious, endearing: not attributes of your typical political agitator. But singer-songwriter-producer-activist Nellie McKay merits the description. Her music is whimsical, colorful, catchy and as engaging as it is restless. Toying with antique genres and yet undeniably contemporary, it flirts with multiple styles of delivery while maintaining a sharp social conscience.

For these and other eccentricities, McKay has gained a devoted fan following. On stage and off, she's an outspoken advocate of animal rights, a friend and ally to any arch political quip and -- lucky for us -- artistically uncompromising.

Susan notes: Thanks to TED for making TED Talks downloadable and embeddable, and for providing the biographical information that goes along with them.

Alisa Miller, head of Public Radio International, talks about why -- though we want to know more about the world than ever -- the US media is actually showing less. Eye-opening stats and graphs.

Alisa Miller is President and CEO of Public Radio International. She oversees the development of some 400 hours of programming a week, bringing challenging radio programs to millions of listeners. She is responsible for making PRI programs such as This American Life accessible through satellite radio, and for spearheading the development of new programs such as the new show The Takeaway. And yes, she is the first woman to take the helm of a public radio network.

Susan notes: Thanks to TED for making TED Talks downloadable and embeddable, and for providing the biographical information that goes along with them.

Singer-songwriter Rokia Traore performs "Kounandi," a breathtaking song that blends Malian instruments with a modern, heartfelt vocal.

Born into a traveling, diplomatic family, Rokia Traore absorbed her own Malian traditions into a world-ranging love of music.

Playing off the griot tradition, she tweaks the traditional Bamana styles by playing her own acoustic guitar and arranging haunting backing vocals. Her smooth sound is punctuated by the heartfelt, raw tone of the n'goni lute and the harp-like kamala.