The Rollkers, a transportation accessory that increases a person's average walking rate up to 7 miles per hour, is seen in use on January 4, 2014 before the start of the 2015 Consumer Electronics Show in Las Vegas, Nevada. 2015 International CES, the world's largest showcase for the latest in consumer electronics, runs on January 6-9, with media preview days on January 4 and 5. AFP PHOTO / ROBYN BECK (Photo credit should read ROBYN BECK/AFP/Getty Images)
