Adam Korbitz writes to point out that SETI@Home has added a new algorithm for use in evaluating signals from outer space. It's called "Astropulse," and they've made the scientific details available. Quoting: "The original SETI@home is narrowband, meaning that it is listening for a particular radio frequency. That's like listening to an orchestra playing, and trying to hear when anyone plays the note "A sharp." Astropulse listens for short-time pulses. In the orchestra analogy, it's like listening for a quick drum beat, or a series of drumbeats. Since no one knows what extraterrestrial communications will 'sound like,' it seems like a good idea to search for several types of signals. In scientific terms, Astropulse is a sky survey that searches for microsecond transient radio pulses."