Frank Sinatra and Malcolm Forbes are living proof that the only difference between men and boys is the price of their toys. Sinatra says he has been hooked on toy trains since his mother hocked her fox fur to buy him one when he was 11. According to USA Weekend magazine, Sinatra has an 18-by-30-foot set-up at his home in Rancho Mirage, Calif., that can accommodate five trains at once and includes a model of his old neighborhood in Hoboken, N.J., an Old West town, a New Orleans riverboat and a billboard announcing a Sinatra concert. Forbes's boyish passion is toy soldiers - 128,000 of them. "our soldiers are in excellent physical condition," Forbes says. "They're easy on uniforms. They don't cost much to feed. They don't disobey at all. Tell them to stand at attention and they'll hold that position for years."