...AUGUST 26: Tennis player Serena Williams attends the Roger Federer, Rafael Nadal, Serena Williams and John McEnroe Challenge on the streets of Manhattan on August 26, 2009 in New York City. (Photo by Bryan Bedder...

...ceremony at the MGM Grand hotel and casino in Las Vegas, Friday, Sept. 12, 2008. Forrest will challenge WBC light middleweight champion Sergio Mora for Mora's title on Saturday in Las Vegas

After 13 months at sea, Zac Sunderland returned ready for his next challenge

...around the globe, David Stern still isn't ready to stay at home. Not when so many challenges remain, so many new opportunities exist to grow the sport

LOS ANGELES - MAY 19: Pau Gasol #16 of the Los Angeles Lakers challenges the shot of Chauncey Billups #7 of the Denver Nuggets in Game One of the Western Conference...

Part of the challenge is to get the boat from the school to the Hudson River

Ryan Sheckler in action during the Skateboard Park final at the 2005 Dew Action Sports Tour 'Toyota Challenge' at HP Pavilion September11th, 2005 in San Jose, California. Fifteen year-old Sheckler won the event and...

Tiger Woods, left, greets Sergio Garcia after finishing the 18th hole of the Williams World Challenge on Sunday, Dec. 3, 2000, at the Sherwood Country Club in Thousand Oaks, Calif. Woods and Garcia...

...during their match against Australia, as a warm-up for the Olympics, at the USA Basketball International Challenge tournament in Shanghai, China, Tuesday, Aug. 5, 2008. The U.S. won 87-76. (AP Photo/Eugene...

...FILE ** Referee Mike Carey signals touchdown following a St. Louis Rams challenge to a touchdown by the Carolina Panthers during the first half of their NFC playoff game in...

...FILE** Tiger Woods tees off on the fifth hole during the second round of the Target World Challenge golf tournament at Sherwood Country Club in Thousand Oaks, Calif., in this Dec. 14, 2007 file photo...

Tiger Woods lines up his putt in the final round of the Target World Challenge golf tournament at Sherwood Country Club in Thousand Oaks, Calif., Sunday, Dec. 16, 2007. (AP Photo/Reed...

New Orleans Saints coach Sean Payton throws the red challenge flag during the second half of their NFL football game with the Saint Louis Rams in the...

Vince Carter hasn't been able to rise up and meet the challenge against the Cavs

Alonzo Mourning can shoot some stick. Just ask Paul Pierce, who Mourning beat in the 8-ball challenge final