Terry Gross

Writer and peace activist Thich Nhat Hanh. Nhat Hanh became a Buddhist monk at age 16, worked on a globally for peace in his native Vietnam during the war, and has written over 75 books on peace. Some of his best-known are "Peace is in Every Step," "Being Peace," and "The Miracle of Mindfulness." His 1995 book, "Living Buddha, Living Christ" (Riverhead) is now available in paperback.

Music legend Johnny Cash. Cash has been recording albums and performing since the 1950's. Representing Cash's varied musical styles, he has been inducted into the Songwriters, Country Music, and Rock and Roll Halls of Fame. He's just released an autobiography called "Cash" (Harper) The book tour for the memoir has been cancelled due to complications with Cash's Parkinson's disease.

Historian Dayton Duncan. He's the author of the book "Lewis and Clark: The Journey of the Corps of Discovery -- an Illustrated History" (Knopf). He also co-produced the PBS series of the same name with documentary filmmaker Ken Burns, and is the author of "Out West" (Penguin), in which he re-travels the Merriweather Lewis and William Clark journey.