You can't say Brendan Fraser doesn't knock himself out for his craft.  On the second day of filming The Mummy in the Sahara desert, Fraser was standing on his tippy-toes with a noose around his neck.  "Make it tighter," he told a stunt coordinator.  "I want to make it look like I'm really strangling."  Then, says director Stephen Sommers, Fraser collapsed in a heap.  "We had just met Brendan," says Sommers, "so we thought, 'Oh, he's a real joker.'  But he was really out.  About a minute later he stood up, saying, 'Oh, sorry about that.'"       That refreshing combination of recklessness and good manners made Fraser, 30, a big cheese to the rugrats who made 1997's George of the Jungle a surprise hit.  The girls who first took to Fraser in 1992's School Ties didn't mind the loincloth look, either, and last year Fraser mad a splash in the art-house drama Gods and Monsters.  But with The Mummy earning a King Tut-sized fortune (it dug up $81 million in its first 10 days at the box office), Fraser reportedly now commands $10 million a film,  "He's that magic combination of a really good-looking man who's funny and yet a wonderfully serious actor too," notes his Gods costar Lynn Redgrave.  "He's going to be big, big, big."          But don't look for this man with movie muscle to crawl through pubs or drape himself with models.  He's happily wed (wife Afton Smith, 31, is a former actress) and decorating their newly renovated contemporary-style house in Los Angeles-- perhaps even contemplating a nursery.  "We're definitely talking about starting a family," Fraser told The Edmonton Sun.  "But I think it's important that we get to know ourselves and each other better."		The local playground may never be the same.  Fraser grabs hold of every role---in movies and in life--- with the intensity  of George leaping to catch a vine.  He photographs everything in sight, often with the vintage Polaroid cameras he collects. Even during a recent guest shot on The Tonight Show with Jay Leno, Fraser snapped away at Portia de Rossi (Ally McBeal) while Leno interviewed her.  Sean Astin, his costar in 1992's Encino Man, recalls that for a scene in which Frasers' defrosted caveman cries at a museums' Cro-Magnon display, Fraser "was so committed to doing it right, even if it was just a dumb caveman."  As a heavy-metal doofus alongside Adam Sandler in Airheads, says director Michael Lehmann, Fraser learned to play guitar, and "he wanted to sing, so I said we'll try it, and if it doesn't work, no big deal.  But he did it."  He showed off his dancing in Blast from the Past, and George required him to work out  "like a maniac," says his choreographer friend Adam Shankman.		He thrives on the challenges.  Born in Indianapolis, Fraser, whose parents are Canadian-Americans, "gets along great with everyone," says his brother Regan, 35, who recently moved to L.A. and is looking for work.  "He's the youngest of four boys--the spoiled one."  The family (brothers Kevin.38, and Sean,36, live in the Seattle area) spent the boys' childhood shuttling among Amsterdam, London, Cincinnati, Detroit and Toronto, thanks to father Peters' job with the Canadian Tourism Commission.  (Peter, 62, and Brendans' mother, Carol, 62, a sales counselor, now live in Seattle.)  "I don't have friends from early childhood," Fraser told Movieline.  "The pattern of my childhood and schooling was always transition, transition, transition."  At age 13, Fraser landed at Torontos' Upper Canada College Preparatory School, which introduced him to acting.  "Even in grade 10 you could see something in him," says Colin Lowndes, 48, who ran the theater program.  "He knew at an early age that he wanted to be an actor."  Principal Doug Blakey says Fraser developed the athletic side he shows on film:  "I remember looking our at him practicing, a solitary figure heaving the javelin with grace and style."  In 1997, Lowndes recalls Fraser returned for a class reunion, but didn't play the star:  "He seemed very much the same guy-except he was interrupted