Paul McCartney promoted the release of his first children's book on Monday (October 3) with a book signing at Barnes and Nobles bookstore on fifth avenue in New York. Fans and press gathered to greet the legendary former Beatle as he arrived. Confronted with a blaze of photographers' flashlights McCartney jested amicably with journalists as they heckled for his attention. "High in the Clouds" for ages 5 and up was inspired by McCartney's interest in literature and the animated film he made in collaboration with Geoff Dunbar "Tropic Island Hum." Animator Dunbar and veteran children's author Philip Ardagh also worked on "High in the Clouds." The book tells the story of Wirral the squirrel, who after his woodland home is destroyed by the villain Gretsch, ventures to find the fabled land of Animalia where all animals live in peaceful freedom. Wirral crusades to free all enslaved animals everywhere with his companions Froggo the hot-air-ballooning frog, Wilhamina the plucky red squirrel and Ratsy the streetwise rodent. Taking nearly 10 years to put together, "High in the Clouds" subject matter reflects McCartney's own personal advocacies. A famous animal activist and vegetarian, McCartney and first former wife Linda raised all their children as vegetarians and were notoriously outspoken about animal rights' issues. McCartney's second wife, Heather Mills, with whom he has a young daughter, recently launched an attack on Jennifer Lopez's use of fur in her clothing line. McCartney is the latest celebrity to author a children's book, following in the steps of the likes of Madonna, Jamie Lee Curtis and the Duchess of York Sarah Ferguson. At 63, however, he has no plans of giving up his day job quite yet. McCartney has just begun a tour in the United States.