Which scale is used for measuring the intensity of shaking produced by an earthquake?

In California, where earthquakes are literally a daily event, we use the Reichter Scale.

Laudy Miss Claudy, To measure the **intensity** of an earthquake (even in California), modified Mercalli scale would be used. Richter scale measures the magnitudes of the earthquakes. The intensity of an earthquake generally decreases as the distance from the epicenter increases; the magnitude, however, remains constant.

Even the news up in Canada refers to the Reicter scale. I'm guessing that since this other scale has been around since 1905, it must be widely used outside North America.