President Obama told the UN General Assembly today that the U.S. is a serious partner in fighting global warming, and that the country has done more in the last 8 months to reduce carbon pollution than any other time in history. He also met with Israeli and Palestinian leaders uring a push forward in the Mideast peace process. Jonathan Marcus is the BBC's diplomatic correspondent and joins us from New York.

A prep school in Massachusetts is in the process of giving away its library books and replacing them with digital versions. Dr. James Tracy is headmaster of Cushing Academy in Ashburnham, Massachusetts and explains the difficult decision. We'll also speak with Jeff Young of the Chronicle of Higher Education about another trend in education:  electronic textbooks.

Heavy rains have pelted the southeast and hundreds of roads and bridges are underwater in the Atlanta area. The town of Dallas, outside Atlanta, had 16 inches of rain in a 48-hour period. We'll speak to Mayor Benjamin Perry of Trion, Georgia, about how that small town is doing after days of rain.

The MacArthur Fellowships, better known as the "genius awards" were announced today and Harvard Professor of Applied Mathematics L. Mahadevan is on the list. We revisit a conversation we had with Professor Mahadevan last year, about his work watching paint dry, fish swim and flags flutter. He brings a child's curiosity to science and says that discovery is "seeing what everyone has seen, but thinking what no one has thought."

The Mexican guitar duo Rodrigo and Gabriela's latest CD, called 11:11, is a collection of tributes to some of their guitar heroes, including Jimi Hendrix and Al di Meola. But Rodrigo Sanchez and Gabriela Quintero play their tunes on acoustic guitars, combing Rodrigo's dazzling lead guitar with Gabriela's rhythm play.