There are many apps for the iPhone in the apps store that take advantage of the iPhone’s built-in accelerometer and these are mainly games.

Well now you can turn your iPhone into a portable seismometer thanks so Johan Nordberg’s iPhone seismometer app.

Measure everything that vibrates, shakes or moves. Or why not an actual earthquake?

Seismometer uses your iPhone’s built in accelerometer to measure movements in two axes, calculate the resulting energy and draw the results on a rolling logarithmic scale.

Seismometer is available for free from the apps store. Itunes link