Another plug-in from Blur, this one turning up in the materials modifier as an extra map.

It's best used as a bump map, and creates a series of clustered lumps placed randomly over the surface of an object. You can control the way the bumps are distributed and their size by using other maps.

The results range from rippling effects like water, or churned up mud to cellular type effects or bumps that look like rock formations.

Note:
You also need to download blurlib to make this work