  The description of thermodynamic phase transitions in terms of percolation
transitions of suitably defined clusters has a long tradition and boasts a
number of important successes, the most prominent ones being in ferromagnetic
lattice models. Spin glasses and other frustrated systems are not among them as
the clusters of aligned spins usually considered in this context start to
percolate in the disordered phase and hence fail to indicate the onset of
ordering. In this mini-review we provide an overview of the state of the art in
this field, including recent advances, and outline the main open questions in
the area.
