It Still Couldn't Have Saved Waterworld

Surveillance technology is usually -- and rightly -- regarded with suspicion. Whatever its utility, we're always conscious of the potential for its misuse, and all too often, surveillance gadgetry serves only to record tragedy rather than prevent it. Still, when some potentially-brilliant technology works as-advertised, it's beyond cool:

A 10-year-old girl in Bangor, Wales, was saved from drowning when she blacked out in a swimming pool, after a set of computer-linked underwater cameras alerted lifeguards. The Poseidon system, currently installed in eight U.K. pools, and over two dozen in the U.S., uses a series of overhead and underwater cameras to track movement in a pool. When a swimmer disappears beneath the surface, software triggers an alert, which can help a lifeguard reach the victim more quickly. In this case, the computer issued an alert within 10 seconds after the girl, who was swimming in the deep end of a 12-foot deep pool, sank to the bottom.