This is the Arduino Seismograph V2.0, this is just the concept of one idea, it's no longer use an piezo buzzer like my previous seismograph (http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1242071531), this one use an optical mouse as the input sensor, of course this idea has some pros and cons.
check the video and more here ->Arduino HN - EV: Arduino Seismograph V2.0 (Concept)