George Plimpton, who lived many lives and wrote about most of them in popular books, died in his sleep Thursday night at age 76 at his Manhattan apartment. Word of his death came from friend Elaine Kaufman, owner of Elaine's, the Upper East Side restaurant that Plimpton, as much as anybody, helped turn into a hangout for writers, politicians, and showbiz celebrities. Plimpton mingled easily in those worlds and others (pro sports, bluebloods), and his presence proved influential in all of them.
Born a patrician and educated at Harvard, Plimpton was an adventurer and a pioneer of what he liked to call ''participatory'' journalism. Living out the sports fantasies of ordinary guys, he got to pitch to Willie Mays, box with Archie Moore, and most famously, play quarterback for the Detroit Lions, an experience that became the bestseller ''Paper Lion.'' (The book became a 1968 movie starring Alan Alda as Plimpton.).
As an actor himself, he made use of his old-money accent and demeanor to play establishment types in dozens of film and TV projects , including such films as ''Reds'' and ''Good Will Hunting,'' as well as ''The Simpsons'' (where he moderated a spelling bee) and ''ER'' (where he played Carter's grandfather). '''The Prince of the Cameos,' they might call me,'' he once said.
Plimpton's greatest legacy, however, may not be the books he wrote but the writers whose careers he helped. Fifty years ago, he founded literary quarterly The Paris Review, which published the early work of such then-unknowns as Jack Kerouac and Philip Roth, as well as landmark interviews with such established writers as Ernest Hemingway and William Faulkner. Never a moneymaker, the magazine was something he did for his own enjoyment, much like everything else he tried his hand at. ''There are people who would perhaps call me a dilettante, because it looks as though I'm having too much fun,'' he once said. ''I have never been convinced there's anything inherently wrong in having fun.''