...DECEMBER 01: A sign of Tiger Woods overlooks the 18th green during preview for the Chevron World Challenge at Sherwood Country Club on December 1, 2009 in Thousand Oaks, California. Woods withdrew from the tournament...

...DECEMBER 01: A sign of Tiger Woods overlooks the 18th green during preview for the Chevron World Challenge at Sherwood Country Club on December 1, 2009 in Thousand Oaks, California. Woods withdrew from the tournament...

THOUSAND OAKS, CA - DECEMBER 01: A sign promoting Tiger Woods at the Chevron World Challenge is displayed off the freeway on December 1, 2009 in Thousand Oaks, California

THOUSAND OAKS, CA - DECEMBER 01: A sign promoting Tiger Woods at the Chevron World Challenge is displayed off the freeway on December 1, 2009 in Thousand Oaks, California

Darron Gibson challenges for the ball during the 2-0 victory

...s Scott Christopherson during the first half of an NCAA college basketball game during the Chicago Invitational Challenge in Chicago, Saturday, Nov. 28, 2009

...Woods walks to the clubhouse after a television interview during the third round of the Chevron World Challenge golf tournament at Sherwood Country Club in Thousand Oaks, Calif., Saturday, Dec. 20, 2008. (AP Photo/Danny...

...Coach Mike McCarthy said Monday, Nov. 23, 2009, that losing the two veterans will be a major challenge to the Packers, who have a 6-4 record and are in the middle of the NFC...

...after they defeated Notre Dame 72-58 in an NCAA college basketball game during the Chicago Invitational Challenge in Chicago, Friday, Nov. 27, 2009. (AP Photo/Nam Y. Huh

...Skate 3's" new team mode allows for team competition through various online challenges

...O.J. Mayo of the Rookie team stand for the National Anthem during the T-Mobile Rookie Challenge & Youth Jam part of 2009 NBA All-Star Weekend at US Airways Center on February 13, 2009...

Sure, playing in front of the Monster is a challenge, but Bay's metrics pale in comparison to Holliday's

LOS ANGELES - NOVEMBER 15: Shane Battier #31 of the Houston Rockets challenges the shot of Kobe Bryant #24 of the Los Angeles Lakers at Staples Center on November 15...

What a luger

CALGARY, AB - NOVEMBER 20: Armin Zoggeler #30 of Italy takes a preliminary run in the Tiscover Challenge Cup during the Veissmann Luge World Cup on November 20, 2009 at Canada Olympic Park in Calgary...

Shay Given makes a well timed challenge on Patrice Evra