Groundskeepers at AT&T Park in San Francisco paint the World Series logo onto the field before the Giants and Texas Rangers started team workouts Tuesday. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

Roy Halladay threw the second no-hitter in postseason history Wednesday, leading the Phillies over the Reds 4-0 in Game 1 of the NL division series. Mel Evan/AP hide caption

itoggle caption Mel Evan/AP

Virginia Tech's football helmets are outfitted with six sensors (the brown objects) that record data. There is also a small antenna that transmits information from the sensors to the sideline controller unit. The sensors are small accelerometers -- similar to devices that trigger an automobile air bag. Courtesy of Dr. Gunnar Brolinson of Virginia Tech hide caption

itoggle caption Courtesy of Dr. Gunnar Brolinson of Virginia Tech