While light normally travels at just under 300 million meters per second in a vacuum, physicists managed to slow it...

While light normally travels at just under 300 million meters per second in a vacuum, physicists managed to slow it down to just 17 meters per second in 1999 and then halt it completely two years later, though only for a fraction of a second. Earlier this year, researchers kept it still for 16 seconds using cold atoms.

Source: http://www.newscientist.com/article/dn23925-light-completely-stopped-for-a-recordbreaking-minute#.UfH-XuydK71