The giant plume of volcanic ash from Iceland is upending air traffic patterns worldwide. Half a dozen European nations have closed their airspaces because of the volcanic ash and 17,000 flights were canceled. The ash cloud has left tens of thousands of travelers stranded around the globe, and blocked the main air flight path between the U.S. east coast and Europe. The BBC's Nkem Ifejika brings us the latest.

As education experts struggle to figure out ways to close the learning gap between lower income minority groups and more affluent whites, one researcher thought motivating kids with cold hard cash might be the answer. This week's Time Magazine chronicles the ensuing experiment, which involved 18,000 kids in four major cities getting paid cash for various kinds of academic achievement. Did it work? To find out we speak with Time Magazine contributing writer Amanda Ripley.

In a move praised by gay rights advocates but criticized by conservatives, President Obama ordered federal health officials to draft new rules requiring that hospitals which receive Medicare and Medicaid payments grant all patients the right to designate who can visit them and who can make critical care decisions. We speak with Art Caplan, professor of bioethics at the University of Pennsylvania.

Grameen Bank pioneered the idea of microcredit in Bangladesh, giving small loans to very poor people to help them start businesses. It's now a world-wide movement with over 150 million borrowers. And Grameen has recently started operations in three U.S. cities, with plans to expand. So how will it work here? We speak with economist and Grameen Bank founder Mohammed Yunus. He won the Nobel Peace Prize for putting the idea of microcredit into practice and is now expanding the model to issues like health care.

Julie Morgenstern is an author and expert on organization. She provides us with her spring cleaning approach - to move beyond the magazines that are piling up in the corner and the clothes that aren't worn any longer. She says you need to think, too, about time clutter.

• The Lickets, "Meat City"
• Christian McBride, "Theme for Kareem"
• Freddie Hubbard, "Gibraltar"
• Jimi Hendrix, "Crosstown Traffic"
• Moby, "Myopia"
• The Ventures, "Pipeline"