  Based on the competition between members of a hierarchy of length scales in
complex multi-scale systems, it is shown how clustering of active quantities
into concentrated sets, like bubbles in a Swiss cheese, is a generic property
that dominates the intermittent structure. The halo-like surfaces of these
clusters have scaling exponents lower than that of their kernels, which can be
as high as the domain dimension. Examples include spots in fluid turbulence and
droplets in spin-glasses.
