As you walk by, the sound of a woman's voice whispers "Who's that? Who's there?... It's not your imagination." Advertisers describe it as a "chilling message."
The technology is created by Holosonic; the device is effectively an "audio spotlight" that can project sound literally right into your ears.
See a video demonstration: http://video.google.com/videoplay?docid=354398010991459626&hl=en