View movie A pulse of light injected into a Bose-Einstein Condensate (BEC) can be slowed to a tiny fraction of the speed of light in a vacuum. In the movie, the top animation shows how the information in a pulse is compressed when it enters a BEC (contained inside the blue arc), and then returned to it's original form as it exits. In the movie, the lower animation illustrates a race between a light pulse that passes through a cigar-shaped BEC blob and a light pulse traveling in free space, demonstrating how light can be controlled with BECs. Techniques that slow light could potentially lead to devices that manipulate light in the same way that microelectronic chips and computers manipulate electrical signals and data. 
Image credit: Chien Liu and Lene Hau, Harvard University