What can be done against bullying?

Inspired by Safie’s question on bullying.
We’re all against it, that much is clear. But what can we do to help prevent it, or even stop it? On a large scale, it seems impossible. Not unless you ruled the world or something…bullying others into not bullying…heh. But in all seriousness, what methods can be used against it? What can one do in one’s community, on the internet, your kid’s school, the workplace? This question applies to both children and adults being bullied. We all despise it, but just saying that is not enough. What can be done?

As I point out above, there has always been bullying and always will be, it’s probably in man’s nature to do so, especially seeing as children do it all the time, but surely there must be something that can be done against it in one’s community. To make it known, to understand what bullying and its many forms are, to understand what it can do to victims, and then to apply some method which might smooth it out significantly.