There's been a lot of buzz lately that instead of listening in the microwave spectrum, SETI researchers should be observing in the visual or near infrared. At these frequencies, tight-beam lasers could transmit messages in a much more energy-efficient fashion. The buzzword is "Optical SETI".

Of course, the fundamental problem still remains, the transmitting civilization must have reason to believe there will be someone looking at him in the system he is signalling to, at the time he is signalling (making allowances for light-travel time). And because of the super tight beams, it is highly unlikely we might intercept a signal meant for someone else.

You know, the more I think about SETI, the more I'm starting to believe it is a waste of time and effort. If you're the last man on earth, even if the last girl on earth lives somewhere within a hundred miles of you, its still next to impossible to hook up with her.