  We analyze properties of local Polyakov loops using quenched as well as
dynamical SU(3) gauge configurations for a wide range of temperatures. It is
demonstrated that for both, the confined and the deconfined regime, the local
Polyakov loop prefers phase values near the center elements 1, exp(i 2 pi/3),
exp(-i 2 pi/3). We divide the lattice sites into three sectors according to
these phases and show that the sectors give rise to the formation of clusters.
For a suitable definition of these clusters we find that in the quenched case
deconfinement manifests itself as the onset of percolation of the clusters. A
possible continuum limit of the center clusters is discussed.
