Procedurally generating wear on an object? What are some techniques for procedurally generating wear (chips, cracks, dents, etc.) on a mesh object?

For example, what are some ways I could do something like this:



but with more dents and detail? (and without having to manually duplicate objects everywhere)



The image above was created by duplicating some smooth shaded spheres with displace modifiers and intersecting with a boolean modifier.
A completely different way of simulating wear on an object, with the benefit of using only Modifiers, is Decimate in conjunction with Subsurf. The attached screenshot shows the default cube simply run through Remesh, Decimate->Collapse, Decimate->Un-Subdivide, then Subsurf. There is a lot of flexibility in this approach; changing almost any of the parameters in any of the modifiers subtly alters the distortions on the cube.