  RuSr$_2$GdCu$_2$O$_8$, in which magnetic order and superconductivity coexist
with $T_{Magnetic}$$\gg$$T_c$, is a complex material which poses new and
important questions to our understanding of the interplay between magnetic and
superconducting (SC) order. Resistivity, Hall effect and thermopower
measurements on sintered ceramic RuSr$_2$GdCu$_2$O$_8$ are presented, together
with results on a broad range of substituted analogues. The Hall effect and
thermopower both show anomalous decreases below $T_{Magnetic}$ which may be
explained within a simple two-band model by a transition from localized to more
itinerant behavior in the RuO$_2$ layer at $T_{Magnetic}$.
