SeisMac looks like a fun freeware program that turns your MacBook or MacBook Pro into a seismograph. It uses the Sudden Motion Sensor to detect vibration, like an earthquake or your clogging routine, and displays it in a three-axis acceleration graph. My Powerbook doesn't have the sensor so I haven't tried out SeosMac yet, but it's a neat idea!
Link (Thanks, Mark Pescovitz!)