Non conventional behavior of transport properties (resistivity , thermal conductivity, surface impedance, critical currents) are often observed in superconductor measurements, with the appearance of anomalous peaks at the transition. Similar effects are also observed in magnetic compounds exhibiting sharp resistive transitions at the Curie temperature and in other systems. Though these effects have been often interpreted in different, complicated ways, in many cases it was recognized and proved that this is due to simple current redistribution effects related to the slightly non-homogeneous nature of the measured samples. In this lecture we will briefly review and discuss these effects and, referring to very simple concentrated constant equivalent circuits, we will show how sample non-homogeneity can easily reproduce all the observed features.