"For five decades astronomers have searched the vast ocean of space in the hope of picking up some kind of radio message from the neighbours. That nothing has been found has not deterred the search for extraterrestrial intelligence, or SETI to the cognoscenti. Despite those years of effort, SETI has done little more than dip a glass into the cosmic ocean, having looked closely at only 750 of the Milky Way’s billion or so star systems. That will soon change. The Allen Telescope Array, a cluster of radio telescopes being built in California with SETI in mind, will dramatically speed up the rate at which such systems can be explored."