Many track fans watched online four years ago, as sprinter Usain Bolt set a world record at the Beijing Olympics. This year, NBC will stream video of all 302 events online. And Bolt, seen here showing his appreciation for video in 2010, will try to repeat his feat. Mark Dadswell/Getty Images hide caption

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Olympic beach volleyball player Kerri Walsh says of this year's Summer Games: "We're feeling really good; we can't wait for London. We want to do what's never been done before, which is three consecutive gold medals." Harry How/Getty Images hide caption

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U.S. Olympic Equestrian rider Phillip Dutton jumps with Zeizos in West Grove, Pa., in this 2010 photo. Dozens of horses will fly from America to England for the 2012 Summer Olympics. Don Emmert/AFP/Getty Images hide caption

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