The Book has no one author, editor, or publisher. Defined physically, it is merely a set of loosely connected, handmade, decentralized notebooks cached throughout the vagabond meccas of Latin America and Asia—a collective, disorganized stash of travel tips, phone numbers, discount deals, crazed illustrations, conspiracy theories, backbiting marginalia, and boozy reminiscence, penned by and for the deeply broke backpackers of the world. It is known sometimes as the Traveler's Book, or the Memory Book, or the Israeli Book, because it depends mostly on Israelis—that new diaspora of young travelers who, with a mean age of 22 and some hard, mandatory military service under their belts, have given rise in the past dozen years to a global sub-tribe of poncho-wearing, sandal-sporting nomads. For the Israelis, the Book is a fluid concept, a kind of viral hypertext flitting from cork bulletin board to pocket notebook, as much an oral tradition as a written one.

Although the Book is scarcely known outside the world-within-a-world of the Israeli travel scene, it is hidden in plain sight. Four volumes are available in a certain laundromat in San José, Costa Rica. Four at an unheralded youth hostel in Bogotá, Colombia, called Platypus. In Peru, the Book is variously located in a travel agency, an upstairs watering hole in Huaraz favored by gringo trekkers, and the House of Fun, a Lima hostel that isn't even listed in Lonely Planet. If you know where to look, the Book is everywhere. Otherwise it is nowhere.

I first heard it mentioned in the early 1990s, by an Israeli paratrooper who'd just arrived in Puerto Montt, in southern Chile. "So where's the book?" he asked another Israeli. The answer, given in Hebrew, was: in a butcher shop run by a Chilean Jew. It took me a decade to understand what he had really said—not "Where is our book?" but "Where is our knowledge? Our community?"

I began to ask for the Book wherever I went, figuring that if anyone would know the best spots—or the least bad spots—it would be the Israelis. More than any other nationality, they have absorbed the ethic of global tramping with ferocity: Go far, stay long, see deep.