Everyone seems to agree this is bad -- and in the wrong hands, it definitely could be.

However, I can think of some great uses for it:

- Very similar to iPhone's "delete", which most people are familiar with. It means "Hey, I can be dragged"

- Could be good for refusing to do an action. Apple shakes the login box when you use the wrong password.

- A tiny notification icon could shake every few seconds to get someone's attention.

- Some logos (a car?) could look cool shaking for a second or two (either right away, or on hover).

- In tutorials, to show a button/element that the tutorial is talking about