Reagan-era wunderkind Jay McInerney has some words of advice for n+1 founding editor Keith Gessen, whose debut novel, "All the Sad Literary Young Men," covers subject matter close to McInerney's own heart—namely, self-absorbed, self-loathing Manhattan males. "Literary fame is a double-edged sword," advised the "Bright Lights, Big City" author when we caught up with him at Chanel's dinner for the Tribeca Film Festival on Monday night. "And you should be careful not to say 'yes' to everything." Given that McInerney did a blogging stint for the Sub-Zero refrigerators Web site last year, the man presumably speaks from experience.