We hear a lot about “joy to the world” this time of year. His Holiness, the 14th Dalai Lama's new book is “The Book of Joy” (Avery). He is the world’s most celebrated monk: a Nobel Peace Prize-winner, and the spiritual leader of six million Tibetan Buddhists … a man with a message of compassion and non-violence so meaningful, and so cool, he’s been featured in Apple ad. The book is based on a series of conversations he had with an equally-celebrated friend: South Africa’s retired Archbishop Desmond Tutu, a pillar of his nation’s struggle against apartheid. They wrote the book with editor Douglas Abrams. It explores a topic appropriate to the season: How to live a more joyous life. As the Dalai Lama sees it, something as simple as a smile can change the world.