In a project that's grabbing headlines this week, researchers at the University of California, Riverside and Stanford University are recruiting laptops to help them monitor seismic activity. The Quake-Catcher Network is a distributed network of laptops running software that takes advantage of a built-in accelerometer to monitor and report seismic activity. (The accelerometer's primary purpose is to detect a fall or shock to the chassis in time to stop the hard drive from spinning, though it's been a key element in several fun hacks, including the Smackbook [video] and SeisMac.)
Based on the same software as the popular SETI@Home project, the Quake-Catcher Network uses your laptop's down time to record and send data to a central repository for analysis. Aside from gathering data, the network also has a significant educational component that's designed to help students better understand earthquakes.
Ars Technica has a detailed writeup of the technology involved, while PC Worldtalked to Elizabeth Cochran, one of the lead scientists on the project. You can download the program (currently Mac-only, with a Windows version to come soon) at the QCN Web site.